Warning in Update Manager Mint 21.1

I’ve been getting this message when updating/upgrading using the Update Manager.
W: http://ppa.launchpad.net/mkusb/ppa/ubuntu/dists/jammy/InRelease: Key is stored in legacy trusted.gpg keyring (/etc/apt/trusted.gpg), see the DEPRECATION section in apt-key(8) for details. I have not figured out how to resolve this.

It’s just a warning, I wouldn’t get to concerned.

if it is bothering you, you can look through /etc/apt/sources.list and comment out the line pertaining to it or /etc/apt/sources.list.d/ and renaming the file.list pertaining to it and try adding it again.

mkusb launchpad - Brave Search