Q: I bought a new computer. I need to authorize the new one to play old content. How do I do that?

I bought an new computer. My Apple ID did not change. I tried to play old content but received a pop-up that in order to play previously purchased songs, the new computer needs to be authorized to play the old content. I checked my Apple account to for a field to do that but can't find anything. How do I authorize my new computer to play previously purchased content?

Thanks for any suggestions or help you can render.