We have one example of feedback form here – https://supsystic.com/feedback-form/
Also you can look through other Contact Form examples on this page – https://supsystic.com/contact-form-examples/
In order to add one more text area field follow the next instruction:
1. Open your Popup admin settings
2. Go to Subscribe Tab and enable subscription
3. Scroll down till Subscription fields and click +Add button
4. Choose field type, fill other field parameters and click OK button
5. And Save changes – http://prntscr.com/fb8082
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