An announcement post cannot be editing in Ecamm Live but can be done on the FaceBook or YouTube website.
For Facebook scheduled lives, open the announcement in your web browser. (You can do this by clicking on the countdown in the bottom left-hand corner of Ecamm Live). Then, click the “Edit details” button on the website to make changes to the post description, scheduled time, and announcement post image.
For YouTube scheduled lives, click the pencil icon in the bottom left-hand corner of Ecamm Live. This will bring up the broadcast's settings page on the YouTube website.