Screen Share using Link, sent through Chat Ticket by PDI CSE Technician
Or Screen Share using Join Code, provided by PDI CSE Technician
Note: *If you are still unable to Share your screen, then please Restart your Computer once and try the same Steps.
Incase if its being block by Firewall Program, try to Allow or try to Turn-Off Firewall.
If this doesn't help, then you may also provide us Remote Access using Team Viewer.