Perhaps read the alternatives that others have proposed, some working right now, this one for example:
Notice below, this Win10 laptop client is on 192.168.0.41 via a Wifi hotspot but is able to use Win File Manager to access remote routing from the My Cloud Home which is on 192.168.1.xx on a different subnet and ISP, copying >100 files in a folder from the MCH. This is made possible by advertising a Tailscale Subnet Router in software from the 192.168.1.xx subnet. Instruction setup in Post 12 below.