Enduser UI with Identity Cloud - X-Frame-Options

[srjturner]

I am running the platform-enduser in development mode (yarn dev) against an Identity Cloud tenant. I have edited the .env file to point to the tenant, and I have created the 'end-user-ui' client app in the tenant also.

When I visit the app in my browser I get the following in my browser's Dev Tools console:

Failed to load resource: the server responded with a status of 400 ()
Refused to display 'https://[mytenant].forgeblocks.com/' in a frame because it set 'X-Frame-Options' to 'sameorigin'.

I can see mention of similar but distinct messages (Refused to display 'https://idm.example.com/admin/appAuthHelperRedirect.html' in a frame because it set 'X-Frame-Options' to 'deny'.) in the Understanding and Troubleshooting ForgeRock Identity Platform Integration community post. But that is in the context of the IDM Admin UI rather than the enduser UI.

What do I need to do to make the enduser UI work with Identity Cloud?