I’ve a Thinkpad that is cellular capable. Can I transfer the sim card to it ; will it function?
As a phone, no. An already activated Republic SIM would probably work in a laptop for cellular data, however, using it directly in a laptop would be contrary to Republic’s Terms of Service. Per Republic’s Terms of Service, Republic SIMs are to be used only in a Republic compatible phone.
If the intent is to use your plan’s cell data for the laptop, you might consider using your phone’s hotspot feature as described by Republic here: https://help.republicwireless.com/hc/en-us/articles/115007228348-Tethering.