How do you upload video on your form

You can accept uploads in your form by adding the file upload field to it, you will find it under the Basic Fields section in the Form Builder:

Here're also some guides related to the file uploads: 

How-to-Create-File-Upload-Forms

How-to-Change-the-Allowed-File-Types-Extensions-in-the-Upload-Field

Changing-the-File-Upload-Size-Limit

Here're also some widgets related to file uploads too: 

https://widgets.jotform.com/category/file_upload 

This guide will help you to add a widget to your form: 

How-to-Add-a-Widget-to-your-Form

However, if you're looking to upload a file to your form and allow your submitter to download it, then it will not be possible, you will need to upload the file to cloud service and then provide the link in the form, you could also attach the file in an email auto-responder, here's a guide that will help you with that: How-to-Attach-a-File-to-Autoresponder-Emails

Hope this helps.