To make development easier, the sandbox environment does not restrict any domains. You can skip this step in
sandbox.
- Log in to the Partner Portal
- Navigate to Settings > Trusted Domains
- Add your domains. You can use a wildcard like
https://*.myapp.com. Non-local domains must usehttpsprotocol.httpis acceptable forlocalhostdomains, although these should only be used for testing purposes. - Save the domains. This could take a couple of minutes to take effect.