Lithium lease in Alberta

A landman affiliated with the exploration company is offering us a Lithium Lease (Subsurface Mineral) on land in Alberta. I am wondering if anyone has thoughts on what range per acre the signing bonus should be? The land is between Calgary and Red Deer. I know this board is mostly for the USA, but we’re having trouble finding any information on Lithium Leases or who to ask or whether to wait. Apparently, they plan to start extracting lithium from subsurface water in the near future.