When you purchase a Premium subscription license, you can choose how many devices you want your license to protect. Do Is this needed? Lifetime licenses, also called Pro licenses, can only be activated on one Windows computer at any given time. To see how many devices your license protects, refer to your Malwarebytes confirmation email or log in to My Account.
My Account a free service - technically it is a service provided with your purchase so not free contains information on licenses you have purchased or renewed through the Malwarebytes website. If you do not have a My Account login, see how to Create and set up your My Account profile.
This needs to be explained differently. I changed the first sentence: If your license was purchased through an online merchant, retailer, or another vendor, contact the vendor to request details about your license.