JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
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This is possible by using the Unique Submission in the Preferences. Please follow the steps below:
1. Click the "Preferences" button in the toolbar.
2. In the Preferences window, go to "Advanced" tab and then choose "Strict Check" as the option for Unique Submission. Strict check controls the IP address.
Related guide: How-to-Set-Unique-Submissions-on-a-Form
Hope that helps. Thank you.