The first part of this reply is constructed using voice to text, which is a method that I usually prefer. Now I will try to post a photo in this message.
So it would appear that you have to select one picture at a time and upload it.
I'm going to make a second attempt right now:
It is difficult to impossible to select multiple photos for upload. The help section says to select an " add" button. However, no such button could I find. According to help, one can add up to 10 photographs, but there is a total file size limit.
Anyway, this is just a test.🤣