I’m really surprised i haven’t seen a venmo plugin, yet given how popular it is and seemingly how many people use it in this new generation. Is it because you cant or its hard to intergrate? Im not a developer, it seems plugin developers are some sort of dark magician or or a blue eyes white dragon.
Venmo no longer has a public API accessible to new users. Though you can likely perform actions with Venmo via the Braintree API (Braintree acquired Venmo. And PayPal acquired Braintree). Your best bet is to look to the Braintree plugins / developers on the forum.