Unable to Print To an HP Laserjet

[Elegant_Emperor]

@RTB

Second:- How can I check if they are set to Main Server?

There is an app called Software & Updates where you can check.

By the way you should add the public key for Microsoft Edge. Here is the tutorial:

[HOW TO] Fix NO_PUBKEY error

Sometimes a manually added PPA could cause update error which looks like below during the update: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY XXXXXXXXXX This can be fixed by issuing the following 2 commands in terminal: gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv XXXXXXXXXX gpg --export --armor XXXXXXXXXX | sudo apt-key add -