Sometimes, your customers may accidentally submit multiple copies of the same form. This may make it hard for you to manage your form submissions.
In this post, we'll walk you through detailed guide on how to prevent this problem from happening with Blue Form Builder for Magento 2.
https://www.magezon.com/magento-2-form-builder.html

Supposed that you create a for with Blue Form Builder.
1. Open the edit page of a form, then open Settings > Advanced.
2. Turn on Disable multiple submissions from same device. Then you'll see 2 other fields appearing:
- Disable Condition: choose a condition which will determine a customer has already submitted the form. It can be Customer ID, IP Address or Form Fields. If you choose Form Fields, you can choose specific fields in your form.
- Message when disabled: enter the message to notify customers that they have already submitted the form.

Remember to save after you finish.