JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
If you mean this lock:
You get it by making your form Encrypted, and to do that please follow this guide.
If you had something else in mind, please let us know and give us more information.