Paypal Adaptive payments don't work anymore.
 https://developer.paypal.com/docs/archive/adaptive-payments/

Before integrating upfront onboarding, you must be an approved partner, and you must have an access token. Then, complete the following steps:

  1. Make a Partner Referrals API call.
  2. Add a PayPal sign-up link on your site.
  3. Seller signs up on PayPal.
  4. Redirect the seller back to your site.
  5. Track seller onboarding status.

But there'is an alternative... smile https://developer.paypal.com/docs/commerce-platform/onboarding/upfront/


https://wedevs.com/18319/paypal-adaptive-payments-add-dokan/


Paypal Settings Dokan  https://docs.woocommerce.com/document/woocommerce-shortcodes/