Spotify repository missing public key

[Mince]

I am running Spotify on my Linux Mint Desktop (21.3 Cinnamon).  I get this error message, which was too long to serve as a title (I was able to edit the question title):

GPG error: http://repository.spotify.com stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6224F9941A8AA6D1The repository 'http://repository.spotify.com stable InRelease' is not signed.

Installed Spotify (system package) on Linux Mint 21.3. The system complains that the Spotify repository is unsigned.
What command do I need to run in the Terminal to correct the issue?

Spotify is working just fine, but I suspect there will come a time to upgrade the package.

I discovered how to edit after I posted the information in a reply.

Thank you.

[Mince]

I posted the error code here after I found it too long for the title above, but then I found how to edit my original post, making this one moot.

[Mince · Accepted solution]

I have a solution to fix my issue.  Spotify for Linux has a code that I can run to configure the repository:

curl -sS https://download.spotify.com/debian/pubkey_6224F9941A8AA6D1.gpg | sudo gpg --dearmor --yes -o /etc/apt/trusted.gpg.d/spotify.gpg

There were two lines, but I had to enter them one at a time, because the sudo took the second line in my Terminal as a very long and invalid password.  Enter your sudo password, then enter the second line:

echo "deb http://repository.spotify.com stable non-free" | sudo tee /etc/apt/sources.list.d/spotify.list

Let all of that run.  Then, you can install the Spotify client:

sudo apt-get update && sudo apt-get install spotify-client

I ended up with a 2024 version of Spotify with more features than I had to begin with.

The site also offers a snap version.  However, I don't use the snap store.