Dell Windows 7 Home Prem OA with Windows 10 Pro Volume license installed having license expired soon issue

Bought a used Latitude E5430 with Windows 10 Pro installed 6 months ago and now it says "license will be expired soon." I did some research and found the volume license was installed but I found the Windows 7 Home Premium product key under the battery compartment which failed when I tried Setting > change product key.

Obviously it's wrong to use Volume license and Windows 10 Pro on this. I would like to have a fresh Windows 10 Home version installed using the DELL OEM product key.

1) how to check if the OEM product key is still valid (same as the product key stored in BIOS or hardware that the software system uses for validate) before spending time for fresh windows 10 installation?

2) what is the correct way to install windows 10 Home? Using Dell windows 10 or MS ?

3) Philip Yip said "The Microsoft website rejects all Dell Windows 7 OEM Keys and you should use the Dell OS Recovery Tool instead." Is this still true?

Thanks