Content Security Policy (CSP) Issue in Outlook Add-In: 'app-name' Scheme Blocked

Question

Overview of the issue:

I encounter a CSP-related issue while integrating the 'app-name' scheme in my Outlook Add-In. Despite updating the manifest and headers, the browser blocks the custom scheme and shows the error:

Refused to frame '' because it violates the following Content Security Policy directive: "frame-src *". Note that '*' matches only URLs with network schemes ('http', 'https', 'ws', 'wss'), or URLs whose scheme matches `self`'s scheme. The scheme 'app-name:' must be added explicitly.

Steps taken:

Added <meta http-equiv="Content-Security-Policy" content="frame-src 'self' app-name:;/> in the template HTML file.

I also added the app name in the XML file

<AppDomain>app-name:</AppDomain>

Platform:

This happens in all platforms and environments

Expected Outcome:

I want to open the app when we click on a button from the add-in