Yes, no problem. You can choose to register in Setapp with your Google or Facebook account and later on use it to log into the Setapp application.
Note that if you've already created a Setapp account using your email, and now you are trying to log in via Facebook or Google, a new account may be created. This happens if your social media and Setapp accounts are linked to different emails. However, if an email is the same, you'll be offered to associate the social media account with Setapp to simplify further logins.