If you saw an error such as
Spotify Error: Existing feed with same name found,
please contact Avod Ops to create this feed.
Spotify recently implemented this bizarre and constraining policy where a podcast can't be submitted to their platform if it has the same name as a podcast that has already been submitted. You'll need to contact Spotify at: firstname.lastname@example.org. Tell them you're a Fireside customer and let them know about the error you're receiving. They should be able to help you out!