How do I use the "submit" option on my website?

Can you please provide more details about your issue? Are you having problems embedding the form in your webpage? Once you embedded the form in your webpage, you can easily fill up the form and hit the submit button. 

Here are 2 helpful guides:
Adding a Form to a Web Page
Getting the Form iFrame Code

Let us know if you're still having issues with the form. Please provide the URL of your page where the form is embedded so we can investigate it. Thank you.