Windows disable HTTPS for custom protocol?

[FrankenApps]

I have a backend API that currently does not have HTTPS yet. I tested my program on MacOS for now, where it used to work fine, however on Windows the requests are blocked:

Mixed Content: The page at 'https://custom.protocol.wry_/' was loaded over HTTPS, but requested an insecure XMLHttpRequest endpoint 'http://myapi'. This request has been blocked; the content must be served over HTTPS.

For production I will use HTTPS nevertheless but for testing purposes it would be great if it could be disabled somehow?