Create a Blazor webassembly project, e.g.:

dotnet new blazorwasm -o BlazorWasmTest

Publish:

dotnet publish -c Release -o output

The base tag in output/wwwroot/index.html needs to be updated. Change this tag:

<base href="/" />

To this:

<base href="https://root-of-github-page/" />

For example, if your GitHub username is johndoe, and your repo name is my-cool-repo, then your GitHub page URL tag will be this:

<base href="https://johndoe.github.io/my-cool-repo/" />

If you want to simplify this, e.g., in a Makefile, use these commands in a Makefile target:

dotnet publish -c Release -o output
 
cd output/wwwroot; sed -i 's|<base href="/" />|<base href="https://johndoe.github.io/my-cool-repo/" />|' index.html

In the repo, enable GitHub pages and add a Static HTML GitHub action as the deployment method. Update the static.yml file for the action as follows: In jobs, deploy, steps, with, path, change path: '.' to path: 'output/wwwroot'.

When you commit, the contents of output/wwwroot will automatically be deployed.