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 your video is on youtube, then you can use the Youtube widget to display a video on your form. Simply enter the URL of your youtube video and it should be displayed to the form thereafter.
You can also check out our other video related widgets here if your video is not on youtube: http://widgets.jotform.com/category/video
Unfortunately, it is not possible to disable the submit button and enable it upon the end of the video. You will need to use custom code to achieve that, and to add the code you will have to download the full source code of the form.
A possible workaround I can suggest would be to add a checkbox to confirm that the user has watched the video.
Then use a Show/Hide condition to show the submit button once the checkbox is checked. Here's a guide that can help: How to Show or Hide Fields Base on User's Answer.
You can check out this demo form to see it in action: https://form.jotform.com/62222209800949.