Hi @Mudhafar Ismael ,
yes, it is possible to connect a custom domain with your Blazor web app. Look at this similar Stack Overflow post.
posting the content of the post on here:
"If you're running Blazor locally you could be doing one of three things:
1.Running directly from the file system, e.g. opening index.html
in the browser. You can't apply TLS (SSL) here because there is no server to decode the requests and encode the responses
2.Running on a local IISExpress server, e.g. via Visual Studio
3.Running the Kestrel server, e.g. via dotnet run
In either (2) or (3) you need a local development certificate. This is exactly the same as any other ASP.NET Core application. It used to be hard but these days Visual Studio will help you out with this when you first run the app.
If you need to set one up, Scott Hanselmann has a useful guide on doing this."
Hope that helps.
Grace