$ sudo apt-get update
Hit:1 http://dl.google.com/linux/chrome/deb stable InRelease
Get:3 http://security.ubuntu.com/ubuntu eoan-security InRelease [97.5 kB]
Hit:4 http://archive.ubuntu.com/ubuntu eoan InRelease
Get:5 http://archive.ubuntu.com/ubuntu eoan-updates InRelease [97.5 kB]
Ign:2 https://download.rethinkdb.com/apt eoan InRelease
Err:6 https://download.rethinkdb.com/apt eoan Release
404 Not Found [IP: 167.172.11.96 443]
Reading package lists... Done
E: The repository 'http://download.rethinkdb.com/apt eoan Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
How can I fix this problem?