Blazor Webassembly PWA not working

Has anyone managed to get a Blazor Webassembly PWA to work with Pages? I have it working fine on Azure Static Web APPs but would like to move it to Cloudflare Pages. If i look at the f12 screen i notice that i have a lot of " valid digest in the ‘integrity’ attribute for resource " which i also get in Azure Static Web Apps. Azure requires a fall back role file to work correctly but i cannot find any docs for the equivalent on pages. Any help welcome