When using your Azure for Students subscription with the $100 credit, you initially get access to several free services—including deploying a web app using Azure App Service. However, the free tier (F1) of Azure App Service does not support custom domains; you’ll only have the default azurewebsites.net domain for your application.
To add a custom domain, you need to upgrade your App Service to at least the Basic, Standard, or a higher tier, all of which offer support for custom domain binding. The great part is that your $100 credit can cover the cost of this upgrade, letting you explore additional features such as SSL support and increased performance.