How to prevent the installation of specific packages in Ubuntu 20.04?

Question

How can i prevent a specific package to be installed?

I have already read the following pages:

• Need to prevent a package from being installed
• https://www.tecmint.com/disable-lock-blacklist-package-updates-ubuntu-debian-apt/
• https://unix.stackexchange.com/questions/459162/how-to-mark-a-package-to-prevent-from-being-installed

According to the first and third links, I placed preferences (which did not exist) in /etc/apt/ with content:

Package: *name*
Pin: origin ""
Pin-Priority: -1

but i doesn't work.

Do new versions of Ubuntu work differently?

I have already tried rebooting and updating.

This is the apt-cache policy *name* output:

*name*:
  Installed: (none)
  Candidate: 7.0-2.1
  Version table:
     7.0-2.1 500
        500 http://it.archive.ubuntu.com/ubuntu focal/universe amd64 Packages

This is the apt-cache policy output:

Package files:
 100 /var/lib/dpkg/status
     release a=now
 500 http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu focal/main i386 Packages
     release v=20.04,o=LP-PPA-yannubuntu-boot-repair,a=focal,n=focal,l=Boot-Repair,c=main,b=i386
     origin ppa.launchpad.net
 500 http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu focal/main amd64 Packages
     release v=20.04,o=LP-PPA-yannubuntu-boot-repair,a=focal,n=focal,l=Boot-Repair,c=main,b=amd64
     origin ppa.launchpad.net
 500 https://packages.microsoft.com/repos/ms-teams stable/main amd64 Packages
     release o=ms-teams stable,a=stable,n=stable,l=ms-teams stable,c=main,b=amd64
     origin packages.microsoft.com
 500 http://ppa.launchpad.net/kgilmer/speed-ricer/ubuntu focal/main i386 Packages
     release v=20.04,o=LP-PPA-kgilmer-speed-ricer,a=focal,n=focal,l=Speed Ricer,c=main,b=i386
     origin ppa.launchpad.net
 500 http://ppa.launchpad.net/kgilmer/speed-ricer/ubuntu focal/main amd64 Packages
     release v=20.04,o=LP-PPA-kgilmer-speed-ricer,a=focal,n=focal,l=Speed Ricer,c=main,b=amd64
     origin ppa.launchpad.net
 500 http://security.ubuntu.com/ubuntu focal-security/multiverse i386 Packages
     release v=20.04,o=Ubuntu,a=focal-security,n=focal,l=Ubuntu,c=multiverse,b=i386
     origin security.ubuntu.com
 500 http://security.ubuntu.com/ubuntu focal-security/multiverse amd64 Packages
     release v=20.04,o=Ubuntu,a=focal-security,n=focal,l=Ubuntu,c=multiverse,b=amd64
     origin security.ubuntu.com
 500 http://security.ubuntu.com/ubuntu focal-security/universe i386 Packages
     release v=20.04,o=Ubuntu,a=focal-security,n=focal,l=Ubuntu,c=universe,b=i386
     origin security.ubuntu.com
 500 http://security.ubuntu.com/ubuntu focal-security/universe amd64 Packages
     release v=20.04,o=Ubuntu,a=focal-security,n=focal,l=Ubuntu,c=universe,b=amd64
     origin security.ubuntu.com
 500 http://security.ubuntu.com/ubuntu focal-security/restricted i386 Packages
     release v=20.04,o=Ubuntu,a=focal-security,n=focal,l=Ubuntu,c=restricted,b=i386
     origin security.ubuntu.com
 500 http://security.ubuntu.com/ubuntu focal-security/restricted amd64 Packages
     release v=20.04,o=Ubuntu,a=focal-security,n=focal,l=Ubuntu,c=restricted,b=amd64
     origin security.ubuntu.com
 500 http://security.ubuntu.com/ubuntu focal-security/main i386 Packages
     release v=20.04,o=Ubuntu,a=focal-security,n=focal,l=Ubuntu,c=main,b=i386
     origin security.ubuntu.com
 500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages
     release v=20.04,o=Ubuntu,a=focal-security,n=focal,l=Ubuntu,c=main,b=amd64
     origin security.ubuntu.com
 100 http://it.archive.ubuntu.com/ubuntu focal-backports/universe i386 Packages
     release v=20.04,o=Ubuntu,a=focal-backports,n=focal,l=Ubuntu,c=universe,b=i386
     origin it.archive.ubuntu.com
 100 http://it.archive.ubuntu.com/ubuntu focal-backports/universe amd64 Packages
     release v=20.04,o=Ubuntu,a=focal-backports,n=focal,l=Ubuntu,c=universe,b=amd64
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal-updates/multiverse i386 Packages
     release v=20.04,o=Ubuntu,a=focal-updates,n=focal,l=Ubuntu,c=multiverse,b=i386
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal-updates/multiverse amd64 Packages
     release v=20.04,o=Ubuntu,a=focal-updates,n=focal,l=Ubuntu,c=multiverse,b=amd64
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal-updates/universe i386 Packages
     release v=20.04,o=Ubuntu,a=focal-updates,n=focal,l=Ubuntu,c=universe,b=i386
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal-updates/universe amd64 Packages
     release v=20.04,o=Ubuntu,a=focal-updates,n=focal,l=Ubuntu,c=universe,b=amd64
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal-updates/restricted i386 Packages
     release v=20.04,o=Ubuntu,a=focal-updates,n=focal,l=Ubuntu,c=restricted,b=i386
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal-updates/restricted amd64 Packages
     release v=20.04,o=Ubuntu,a=focal-updates,n=focal,l=Ubuntu,c=restricted,b=amd64
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal-updates/main i386 Packages
     release v=20.04,o=Ubuntu,a=focal-updates,n=focal,l=Ubuntu,c=main,b=i386
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
     release v=20.04,o=Ubuntu,a=focal-updates,n=focal,l=Ubuntu,c=main,b=amd64
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal/multiverse i386 Packages
     release v=20.04,o=Ubuntu,a=focal,n=focal,l=Ubuntu,c=multiverse,b=i386
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal/multiverse amd64 Packages
     release v=20.04,o=Ubuntu,a=focal,n=focal,l=Ubuntu,c=multiverse,b=amd64
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal/universe i386 Packages
     release v=20.04,o=Ubuntu,a=focal,n=focal,l=Ubuntu,c=universe,b=i386
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal/universe amd64 Packages
     release v=20.04,o=Ubuntu,a=focal,n=focal,l=Ubuntu,c=universe,b=amd64
     origin it.archive.ubuntu.com


500 http://it.archive.ubuntu.com/ubuntu focal/restricted i386 Packages
     release v=20.04,o=Ubuntu,a=focal,n=focal,l=Ubuntu,c=restricted,b=i386
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal/restricted amd64 Packages
     release v=20.04,o=Ubuntu,a=focal,n=focal,l=Ubuntu,c=restricted,b=amd64
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal/main i386 Packages
     release v=20.04,o=Ubuntu,a=focal,n=focal,l=Ubuntu,c=main,b=i386
     origin it.archive.ubuntu.com
 500 http://it.archive.ubuntu.com/ubuntu focal/main amd64 Packages
     release v=20.04,o=Ubuntu,a=focal,n=focal,l=Ubuntu,c=main,b=amd64
     origin it.archive.ubuntu.com
Pinned packages: