Turning a generic listing to branded listing

I have a lot of momentum and would really prefer not to restart on a new listing. I had no idea what I was doing at the start, and I listed it generic with/ a GTIN exemption, having Amazon brand approval.

As of tonight, I have Amazon pending Brand Registry because I finally registered my trademark.

I’ve seen posts about people being able to merge their listing into a branded listing, and some have not been able to.

Any tips you can give me would be greatly appreciated.