IIRC, the ‘one device in the chain’ can be the cable, if the license is built into it. (Pluggable has one…but it’s only 10Gbps)
p.s. Since you’re running Windows on both systems, you can just use Thunderbolt networking / Network over Thunderbolt. After plugging in any Thunderbolt cable, give the following an IP address on both ends (You don’t need a TB Share license for this):
Are you talking about the “Easy Share Cable”? That would be a USB4 20 Gbps cable. Also the license that is included when you buy that is for some third party software and not TB Share.
Intel just made a stupid decision to couple the licensing solely to hardware. They should at the very least offer a software license to be bought, similar to how you can buy a Dolby Atmos for Windows license. It can still come included with specific devices.