How to fix, GPG error on apt update

Open your terminal and run the following command to download the key:

Alternatively, you can use wget to download the key and add it manually:

sudo apt-key add RPM-GPG-KEY-mysql-2022

After adding the key, update your package list:
sudo apt-get update

[ErsinAkyuz]

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys B7B3B788A8D3785C
or
then
sudo apt-key add RPM-GPG-KEY-mysql-2022

and try to update again with
sudo apt-get update