My recommendation is that both of these are financial markets that that requires knowledge although in terms of technical ability they both uses similar analysis or techniques such that someone with the knowledge of technical analysis from forex can implement that to crypto. But whole trading strategy is beyond just technical analysis which is where most traders who jump from one into the other fails to understand.

There is fundamental analysis which is mostly based on the fundamentals knowledge you have on that market someone who is deeply into crypto cannot have the broader knowledge of the forex market and a shallow fundamental knowledge most at times affect trades, so personally I usually tell people to stick to their niche if you have been in crypto and just wish to start trading then stick to crypto. If you’re into forex stick to it before jumping ship. Although there are people that do both but it requires sufficient knowledge for both.

Other than this they both different just that cryptocurrency has many pairs when compared to forex and it is 24/7 trading no weekends like forex or country time closes