During integration with Alexa API i faced with an issue during account linking. API successfully redirects to my login page, but after entering credentials and redirecting to https://pitangui.amazon.com/api/skill/link/XXXXXXXXXXXX?state=eyJpbml0Vm....0a1hXbXJl&code=5eeaa8f35d0744779c1f56d0e5a26467
I receive generic error "An error occurred while attempting to link Alexa with external provider".
I use self-signed certificate generated for my domain. Certificate was generated using steps from doc page "Configuring Your Web Service to Use a Self-Signed Certificate" | "https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/testing-an-alexa-skill".
Please help to solve this issue.