Before you can load the fields on your page you must register the domain where you will be loading the fields. You can register your domains through the Partner Portal. You should register all domains where you plan to load the fields.
To make development easier, the sandbox environment does not restrict any domains. You can skip this step in sandbox.
  1. Login to the Partner Portal
  2. Navigate to Settings > Trusted Domains
  3. Add your domains. You can use a wildcard like https://*.myapp.com. Non-local domains must use https protocol. http is acceptable for localhost domains, although these should only be used for testing purposes.
  4. Save the domains. This could take a couple minutes to take effect.
Now you are ready to start a session.