When you use Intuit to log in to Liquid, Liquid uses your first name and last name as defined in Intuit.
To change your name in Intuit, go to the Personal Info section in Intuit and change your Name.
Then, the next time you log in to Liquid, your updated name in Intuit will be pulled in to Liquid.
If you log in to Liquid with an email address and password, you can follow these instructions to change your name in Liquid.