I need to integrate a payment api, nonexistent in wix providers.

How to integrate an Ecuadorian payment api (Datafast) in wix, it is not in the list of wix payment providers, the api requires a development environment for testing, does wix have the possibility to have this development mode?

Mauro, I’m not sure if I understand your question. Wix Velo IS a development environment. Usually these API give you 2 keys, 1 for developing/testing, 1 for production. You just start with the first and (after a possible certification process) then the second. Make sure to store them in Secrets Manager and retrieve them from code.
BTW: hooking up payment API’s is not beginners stuff, it’s far from trivial, let alone the certification for storing credit card numbers (tip: don’t).