How to cross play pc and ps5

Sorry I am sure this is somewhere on here. I know mtx doesn’t carry over crossplay. How to I get my 2 accounts (ps5 and pc), both which have early access accounts purchased, merged. I don’t even know where to start. If someone could be kind enough to help my dufuss brain I’d appreciate it lol

I'm also curious about this. I bought it on PS5 and wanted to play on my laptop when on the road but I don't want to purchase another key.