Your Spotify URI button is not your Spotify URL link. They are different.
Your URI should look similar to this: spotify:artist:0XHiH53dHrvbwfjYM7en7I
Right-click any song, album, artist, playlist, podcast or episode in the Spotify player and select “Share”. Click on ‘Copy Spotify URI’ to copy the Spotify URI.
Go to your AZ Musicians artist profile and edit your profile. Paste the exact URI into the Spotify Follow Button area of your AZ Musicians artist profile. Check your profile (near the bottom) to make sure that you now see a Spotify Follow button that links to your Spotify account.