Validated Excel addin manifest works in Excel locally but not in excel online

I am using Office.js to create an Excel add-in. I am hosting my website on https://localhost:3000 and installed the office dev certs.

When i sideload the manifest.xml locally with office-addin-debugging start manifest.xml desktop, the addin works fine.

However, when i want to sideload the add-in by uploading the manifest on excel online, i get the following error:

I validated the manifest using office-addin-manifest validate .\manifest.xml and it specifically say that it is targeting Excel online and it is valid.

Here is a gist of the manifest and the validate output.

I already checked Excel JS Add-In works in Excel but not Excel Online and it does not seem to applicable in my case, as i am not using visual studio F5 options.

Any help would be greatly appreciated, cheers.

Edit: It may be also important to add that the same manifest file sideloaded a few days ago without errors on excel online.

Just one tip, you can open the Developer Tool by F12, in the Console log, you could see the most error logs.

For this case, the error message is:

Invalid manifest from addincommands dev catalog. Exception details: {"name":"AddinManifestError","message":"AddinManifestError: resid: Commands.Url not found"}

After adding "Commands.Url" under , the manifest was side-loaded correctly...