Here is a video showing how it’s done:

Step 1. Configure Paypal on Settings > Team > Configuration

Create a PayPal app, then copy and paste Client ID from this PayPal page

Once you copy the Client ID from your Paypal account, copy to Dubb here.
Step 2. Configure a New Dubb Call-to-Action > Payments (select Confirmation Message or Redirect URL)
Step 3. Add CTA to a Dubb Action Page
These pages will serve as great landing pages for emails, advertising campaigns, and more…