How do I find out the name of the client seeking freelancer's work? I don't see it on the job posting, but would like to use the person's name in putting in an application. Any help much appreciated.
It is not Upwork's intention that you have the name.
Clients don't expect you to address them by name when you send a proposal. You don't need the name at that point.
As has been pointed out, it may be possible to find a client name by looking at past feedback. I have never done that.