When you initially sign your organization up for Sigma you will be able to choose your organization name and it will be added to the end of your Sigma URL! If you would ever like to change your organization name you can go into the admin settings to change it around.
@Ryan - Thanks! I was really wondering if we could have something like
my_company_name.sigmacomputing.com but you’re right it looks like the only option I have is going to be of the form