A master account contains your SignCut Pro 2 user details such as basic account holder information, Pro 2 subscription (edition and expiration), e-receipts and list of linked computers under your primary subscription.
To create a master account, please open SignCut Pro 2, click on the Account menu then select My Account. Scroll down and click on the Create a Master Account button. Once done, supply your email address and preferred password and proceed to click on Create Account to finish. The master account is now successfully created and you may access it through the same Account menu then select Login to Master Account.
Here is a video for your reference.