A free and open-source web framework that enables developers to create web apps using C# and HTML, developed by Microsoft.
Your chosen frameworks and languages do not require a license, though jquery does not play well with Blazor. As MudBlazor is a 3rd party, they are free to change their license requirements.
For cloud deployments you can use hosted services and not require licenses. For on premise or hosted VM you will needs a SqlServer license, and depending on the hosting O/S an operating system license.