Hello,
Thank you for contacting the PayPal Sandbox Community.
If you have added the correct return url, terms and conditions url, and privacy url and you still cannot add Connect with PayPal to your sandbox app, you may want to consider upgrading to a Business Account.
Connect with PayPal for Sandbox will allow you to request any information that you would like. You have to ensure that you have the three valid URLs in the application.
Thank you,
Jennifer
... View more