A customer is created in Turnstile when you generate a quote, invoice, or subscription for them. If you've integrated with a CRM, creating a new customer in Turnstile will also create that customer in your CRM.
To add a new customer, type the name of the customer in the Select customer field of a new quote, invoice, or subscription and choose + Add [cutomer name] when creating a quote, invoice, or subscription.
New customers will show up in the customers list once they have a finalized quote, invoice, or subscription.