Hi there,
Thanks for reaching out.
WoodMart licenses work on a “one license per live website” basis. You can use the same purchase code on two domains only when it’s the same site: one live domain and one staging/development domain. For a staging copy (including a subdomain used only for testing), activate the license with the Development Domain option checked in the activation screen (WoodMart -> Theme license or during the setup wizard).
If your subdomain is a separate live B2B portal but it still a part of the same project, you can use the same license. But technically, you will not be able to activate it twice. Only if you set the B2B portal as a development copy.
Kind regards,
XTemos Studio