Brand registry question

I currently sell Product A on Amazon as “generic”. I own the trademark which is registered to my second company, that only sells from shopify.

Now, as the trademark is registered to my other company, does this mean i need to open another Amazon account under that company? Or would brand registry be possible in this situation.

My plan was not to have 2 separate companies but due to supplier issues i have had to stick to one product.

Any help would be appreciated, many thanks, god bless