You can create an account by browsing to marshcoding.com and by registering here.
Alternatively you can create an account using the Marsh 241D App on your phone.
See this article for how to download and install the 241D app
When you launch the App, you will see the Home screen.
Simply swipe left to right and slide out the Account panel, then select Account and follow the on-screen prompts.
During the process of registering for an account, you will be prompted to enter your mobile phone number and then click 'Send Code'. You will then receive a Verification Code by text message on your phone. You can then enter that Verification Code and complete the remainder of the Registration. You then have your Account, and can Sign In for future purchases.