I am trying to exit screen share and need to take off black hidden blocks to continue payment options. How do I do this?

Screen share should automatically close out when you end the conversation with the agent.  If it did not, you can close out of your browser and then log back in. If the black boxes are still there, then you can close back out and clear your cache and cookies and then log back in.  This should remove any black boxes that are still there.