Can I host blazor server side using signalr service without using Azure?

Yes, you can host and deploy the blazor server-side application without using Azure but by using AWS or Firebase. Here you can find the steps for hosting the blazor application using AWS.

• Create the Blazor application 
• Publish the application using the context menu from the Solution in Solution Explorer in Visual Studio.

• Click Publish. If there is no error, your application will be published successfully.

Host the application to AWS: https://topswagcode.com/2019/03/05/Hosting-Blazor-Apps/#AWS

Host the application to Firebase: https://dzone.com/articles/hosting-a-blazor-application-on-firebase