OK, long story short, I had to upgrade my Linux distro because it had developed dementia (LOL) and set up a brand-new Bitcoin wallet. Now instead of just showing me the address, the Receive tab shows me a Request Payment thing. I know this is gonna sound stupid, but how can I just get one of the addresses attached to my Bitcoin wallet so I can use it for things like creating an ad on Anonymous Ads?
Your addresses are listed under File -> Receiving Addresses[1], click "new" if you need more. Make sure you create a backup after you set a password and at least every 99[2] requested addresses.
[1] Assuming bitcoin core here, because of "receive tab"
[2] once you set a password the old unused private keys are lost. A wallet.dat file comes with 100 pregenerated keys.