Set TaxKeyword to file

I've been working with the TermStore in Microsoft Graph, using the official documentation I've managed to get a CRUD system of Terms. The whole point of the TermStore is using these terms with files, so I thought it would be also easy to add those terms into files, foolish of me to think that. I've tried to search, and I didn't find any way to do that, I know using the SharePoint REST API or CSOM or PnP is possible, but it feels to me very anti-intuitive, why Microsoft would give the possibility to perform CRUD operations on terms, but then there is no way to add those terms into files? Maybe it's just me that I didn't find how to do it.

This is what I've tried:

If I make this HTTP call, the object that I receive doesn't show the Taxonomy property, so I can't make a PATCH call to modify that value because it simply doesn't appear.

GET https://graph.microsoft.com/v1.0/sites/{site-id}/drive/items/{item-id}?expand=listItem

And if I do this HTTP call, the object has the Taxonomy property

GET https://graph.microsoft.com/v1.0/sites/{site-id}/lists/Documents/items/{item-id}?expand=fields

So I've tried to make a PATCH, sending this to the body

{
    "fields": {
        "email address removed for privacy reasons": "#Collection(microsoft.graph.Json)",
        "TaxKeyword": [
            {
                "Label": "Test1",
                "TermGuid": "1b20b62d-7ee9-4f55-9ecf-88e622a3f7d7"
            }
        ]
    }
}

(I am using an existing Term that I've created with the CRUD system, but I don't know how to get the WssId, I am not sure if it is necessary or if it is even possible to obtain it)

But it appears the generic error "invalidRequest".

And is not a problem of permissions, my app has Files.ReadWrite.All, Sites.ReadWrite.All and TermStore.ReadWrite.All

I hope that there is a solution, and it's just me that I can't search well

Thank you