Graph API url to target a specific file in a specific site

Let’s say I have a file located in https://mycorp.sharepoint.com/sites/somesite/Shared documents/General/MyFolder/myfile.xlsx.

How to reach this file using a graph request ?

I tried : https://graph.microsoft.com/v1.0/sites/mycorp.sharepoint.com:/sites/somesite:/drive/root:/General/MyFolder/myfile.xlsx.

But it fails with "code": "BadRequest","message": "Url specified is invalid." error.

The furthest I can reach without error is the library itself : https://graph.microsoft.com/v1.0/sites/mycorp.sharepoint.com:/sites/somesite:/drive.

How to fix my request?

EDIT: If I use the ID of the site instead of the relative path : https://graph.microsoft.com/v1.0/sites/mycorp.sharepoint.com,aaf8a27d-dcc4-44e7-a9c9-a9124a4bb7f7,bb706eb0-ebd1-42f7-ee5a-97230eaf447c/drive/root:/General/MyFolder/myfile.xlsx

it works as expected. But I my context (no code platform), I may be painful to retrieve the site IDs then get the file in a second request