Hi , I presume is a video related device or application , anyhow seems to me the Seller is asking for access to video that depicts the issue for validation of your claim , and so justify them accepting your claim for replacement or refund and so initiate their inhouse warranty process

Is the downside of remote location online sales

As such you can record video of the issue using your mobile phone or cam or even possibly using a screen capture app such as AutoScreenRecorder 3.1 (freeware) by Wisdom-Soft , save to computer , then upload to online storage such as Photobucket

Note the link in your claim and also the ebay item number - include in your submission request of their advice regarding resolving the depicted problem

Submit via "my ebay" not private email with copy sent to private email - so ebay has record of dialogue in the event of a dispute and the seller is reminded of ebay Seller obligations

Not-for-sale2016 may have additional suggestions

regards

rogespeed