Photohop Elements Editor not opening

I can access Photoshop Organizer however Editor 2021 will not open.  I have an order Number but no serial number and I'm stumped.

My husband used to be my go to IT guru however he passed away 2021.

I've changed account name to myself, hope I haven't messed things up.

I do digital photo books and need Elements.

Can someone walk me thru whatever I need to do.  Thanks