Thank you for reaching us!
The error message you received indicates that the URL you provided for the relying party in your custom policy is not a valid HTTPS URL. This is because the URL you provided is a private IP address, which is not a valid URL for the relying party.
To add a private IP or local private IP address to the Journey framing in the relying party in Azure AD B2C custom policy, you need to use a valid URL that starts with "https://" and points to a publicly accessible endpoint. Private IP addresses are not publicly accessible, so you cannot use them as the endpoint for your relying party.
you can use a publicly accessible domain name for your relying party. once you have a valid URL for your relying party, you can update your custom policy to use that URL in the Journey framing for the relying party.
Hope this helps. Do let us know if you any further queries by responding in the comments section.
Thanks,
Akhilesh.
If this answers your query, do click Accept Answer
and Yes
for was this answer helpful. And, if you have any further query do let us know.