There are different ways to verify GPG signatures and different programs can be used but the concept is the same.
Stick to one guide so you don't get confused.

If this guide is too complicated for you then I recommend the YouTube video by Binance Academy.

There are other programs for almost all other distros too. Some of them may require a license tough.
For more details:
https://blog.kernelcare.com/avoid-death-taxes-and-linux-server-reboots-kernel-updates-3-different-ways