Imac migration and Parallels installation problems

Hi. Be very grateful for help as this problem is very urgent and cant get a response from Parallels via Messenger. Ive just migrated from imac running Big Sur to a new imac running Monterey. I was on Parallels 16 and this migrated across but got a message upgrade to 17 which i didnt and typed use current. Then get a pop up asking for administrator name and password. Ive put in what i was sure it was but wont accept that.
So i thought id upgrade to Parallels 18 to see if that fixed it but the same problem. How do i find out/reset the admin name and password or what am i doing wrong. I urgently need to get parallels up and running on new mac as buyer of the other one is coming to collect and I cant do without accounting software.