I want to ask if is it possible to add some html code or text to the lightbox? I want to add some explanation and instructions about how to use the tool.
no, this is not possible. You could use the info button for that if you like to.
where is the info button? I would like to add an explanation and instructions to the page.
you can drag the info action button into the UI Layout you are using and change the text in the labels settings.
I was trying to do the same thing as well. I added the info action button into place, and changed label settings. But I just get the info icon (with the i ) and it just blinks repeatedly, even when clicked.