can't join campaign

Quote from El_Cid_xxviii >>

I am the DM and would like to add one of my characters to a campaign I'm running.
My character is viewable in Beyond and obviously, I am running my own campaign.
So, how can I add my character to my own campaign?

The same way a player would. Go to the join link for the campaign (the URL you would give to your players to join it, which is visible at the top right of the campaign screen) and add one of your characters from there.

(For future reference, it's usually better to create a new thread if you have a question, rather than posting in an unrelated thread from 9 years ago.)