You won’t be able to move it
I mistakenly set this up on a secondary Apple ID and then tried to get my account moved to my primary Apple ID; but multiple emails, the most recent of which was sent in April 2023, have gone unanswered. Based on this lack of response to multiple emails, I attempted to reach out to them through social media as well; but that also went unanswered. My sincere recommendation is do not ever buy anything through the app unless you will never need to move it to a different account. The automated process doesn’t work and the vendor doesn’t reliably respond to help requests. I’ll be removing the app because the frustration has exceeded the amusement it once offered and there’s nothing encouraging any optimism of a likely remedy.