No pubkey / Jammy / 6.6 / repository not updated

[cerulean]

I'm not sure how to fix the PUBKEY issue

It looks like you have at least two problems, as well as the NO_PUBKEY there is also an error caused by the transmissionbt PPA.
If you need any help with the PPA error, let us know.

For the google chrome issue, can you run a command to check the key on your system ?
Open a terminal by pressing Ctrl, Alt and T together.
In the window that opens type or paste in this command followed by enter

Code:

file /etc/apt/trusted.gpg.d/google-chrome.gpg

Please post back the outcome.

Thank you for responding! 

The line of code you sent returned the following - 

Open PGP Public Key Version 4, Created Tue Apr 12 05:51:15 2016, RSA (Encrypt or Sign, 4096 bits); User ID; Signature; Open PGP Certificate 

I don't know if it's relevant but I don't have google chrome on my computer - I use Firefox for everything. Do you think that could be part of the problem? 

Thanks again!