The link showing the specifications you've provided in the question gives the information that your machine has a dedicated NVIDIA GPU. That's the reason why I will provide you with instructions how to deactivate an AMD and a NVIDIA GPU in order to make only use of the integrated GPU.
1. variant - In case your PC has a NVIDIA GPU (as provided in the specification link)
Open a terminal and execute the following command : sudo nano /etc/default/grub
Add nouveau.modeset=0
to the line : GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
So that it reads : GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nouveau.modeset=0"
Press Ctrl + X to close the file and confirm the change by pressing Y and Enter.
Then execute this command : sudo update-grub
(to update the GRUB configuration)
2. variant - In case your PC has an AMD GPU (as provided in the title of the question)
Open a terminal and execute the following command : sudo nano /etc/default/grub
Add radeon.modeset=0
to the line : GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
So that it reads : GRUB_CMDLINE_LINUX_DEFAULT="quiet splash radeon.modeset=0"
Press Ctrl + X to close the file and confirm the change by pressing Y and Enter.
Then execute this command : sudo update-grub
(to update the GRUB configuration)
Restart the PC, now you are using the integrated GPU only, the dedicated GPU is disabled.