In our app, we are trying to implement a payout feature. If the user correctly performs Action A, we want to be able to pay some incentive money to this user, assuming the user has already connected his account to PayPal or Venmo.
How can I implement this, do PayPal and/or Venmo SDKs/APIs make this possible?
Venmo does not allow you to send money from a business to customers. PayPal does, I believe. You should do this from a backing web service, rather than the app itself. To complete the payment from the app, you would need to embed your account information in the app itself, which would be a security disaster.