When using the APEX you will have to authorize the FormTitan end point.
Following are the steps:
1- Login to your salesforce account.
2- Press on "Setup" link in the upper menu.
3- Type 'Security' in the searchbox on the left.
4- Click on 'Remote site settings' link.
5- Click on 'New remote site' button to create a new endpoint.
6- Give this remote site a name: formtitan, for example.
Enter the remote site URL: https://formtitan.com
7- Save the remote site URL.