If a client hires you with an hourly contract, it is perfectly reasonable for him to ask you to make a video. If you know how to make a video showing your process, then go ahead and do it. Log time while doing it.
But you don't have to if you don't know how to make a video. Or if you don't want to. You can tell the client that it is not a service that you provide.
Personally, I have no problem with a client hiring me with an hourly contract and asking me to teach him my techniques or let him watch live, or write up instructions, etc.
But a client should ask before hiring the freelancer. If the client doesn't specify this part of the job before hiring, then the client needs to be understanding if a freelancer says no.
For a fixed-price job: A client may NOT hire a freelancer to do design work and then ask for a video on top of that. This is asking for free work. This is a violation of Upwork TOS.
If a client did that to me, I would politely explain that such a request is a violation of Upwork TOS, and I can't do it. But I would offer to finish the current fixed-price contract and then do a new hourly contract. Or I would give the client the option to release remaining escrow money immediately and start a new hourly contract immediately, and the hourly contract could be used for simultaneously doing design work and creating videos or training the client.
