You can go to Distribute tab, first make your form status open by click Open button, and then click Email link button, then your default email client opens with the Form URL in the message body. Enter the email addresses of your respondents and optionally edit the subject or message content. When the recipients receive your email and click the link in the body of the email, the fillable form opens in a browser window.
You can find more information on how to distribute your form from Formscentral Help
Hope it will help you!