how to check my customer portal

I'm not sure what you're referring to as a customer portal. JotForm is an online form builder, and technically, a customer portal is something a CMS/CRM platform would have.

If you're wondering how you can view the Submission of your respondents/users, just follow the guide I'm linking below.

Complete guide: How-to-View-Form-Submissions

In case we misunderstood your question, just get back to us with a bit more info and a clearer description of what you're trying to do so we can better assist you.