Considering videos are quite different in terms of file size, etc I would suggest not to try and rely on Shopify to handle this.
You could easily embedd a third party for (jotform as an example which is free for most scenarios) and have it appear after they checkout on the thank you page.
Additionally if you are simply asking them to send a link to their video on say vimeo or youtube, this is an easy aspect to add via line item properties directly to your product page.
Thanks Carlow, I agree that the file upload needs to be specific as video uploads are different. I dont want customers to have to upload to youtube and send us a link as I think thats messy. How do i go about adding a jotform? I have seen shopify experts talk about this, however when I tried to do it I just got more confused!
If you're looking for Checkout customization then it would be possible only with Shopify Plus plan and there are some restrictions so let me know if you found a right solution either we can think for some other solution.
I am interested discuss further with your expectation
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