Note that you will need a Paypal Business account to use Paypal Checkout.
Step 1: Go to https://developer.paypal.com, click "Login to Dashboard" and login with your Paypal business account credentials.
Step 2: Navigate to "My Apps & Credentials".
Step 3: Click on "Live" in the Sandbox/Live selector and click Create App under the "REST API apps" section.
Step 4: Under "App Name" enter "MembershipWorks and click Create App.
Step 5: Note down the Client ID and Secret (click "Show" to see the Secret).
Step 6: Under the Live App Settings enable Advanced Credit and Debit Card Payments (with any sub selections you wish to enable), Vault, Paypal and Venmo, Native Checkout SDK, Subscriptions and Transaction Search, then click Save.
Step 7: In MembershipWorks navigate to Organization Settings > Integration. Under Payments select Paypal Checkout as the Payment Gateway, then enter the Client ID and Secret from step 5. Click Save & Continue at the bottom of the page to save your changes.