How to distribute an Excel add-in created with Blazor?

Dear Enrico Rossini

Thank you for reaching out to Microsoft Q&A Forum and sharing your progress. I can see you've made significant strides and are now at the crucial step of distribution. It's a very common point of confusion for developers new to the Office Add-ins platform.

First, you need to publish your Blazor app and host it on a web server

• The GitHub sample you're using is configured for localhost, which is only for testing and development. 
• You must host the Blazor application on a web server, and the manifest file will simply point to the URL where your application is hosted. It is recommended hosting Blazor WebAssembly app using Azure Static Web Apps 

You do not upload your Blazor WebAssembly application. You only upload the manifest file (manifest.xml) to the Microsoft 365 admin center (for internal distribution) or the Microsoft Partner Center (for AppSource).

• The official guide: Deploy and publish Office Add-ins - Office Add-ins | Microsoft Learn 

You can use the Microsoft 365 Admin Center to deploy your add-in across your organization. Users in your tenant will see the add-in in Excel automatically. Please refer to: Deploy add-ins in the admin center - Microsoft 365 admin | Microsoft Learn 

Since you have a Microsoft Partner Center (formerly MDP) account, and if you plan to make your add-in available to users outside your organization, you’ll need to submit it to AppSource. The manifest and supporting materials are submitted for validation. Microsoft will then review and validate your add-in before it's published to the AppSource marketplace. For more detailed instructions: Publish your Office Add-in to Microsoft AppSource - Office Add-ins | Microsoft Learn

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