Redirect to an app after authentication

[justinsumida]

I am trying to setup a redirect back to a mobile application after authentication.
async redirect({ url, baseUrl }) { const deepLink = 'myApp://Search'; return${deepLink}; },
When I do this, I get an INVALID_CALLBACK_URL_ERROR.
My question is can I define this as a "valid" callback url to redirect back to my application?