Welcome!
You could make an array of all blacklisted song names in your Spotify INIT button so it’s initiated as soon as it runs.
Then in your SR button the requested song name will be saved in a variable called ‘trackName’. You could use Array Find command to check whether the trackname is in the array of all blacklisted songs before adding it to the queue. That would be on line 67, before the ‘Add the Track to queue’ command. 
Hope that makes sense! If you need any further help, feel free to join our Discord at https://discord.gg/dXez8Zh :)