How to create a Facebook post?

I've spent the last hour trying to use this web-based software and have concluded that it simply does not function. If any one has actually used this softwarer for the practival purpose of creating a simple Facebook post, I've be grateful to know. Otherwise I'm moving on! My (time-consuming) experience so far:

> I finally found a "blank" Facebook post in the marketing materials (it is not available by a search within the software, which only has pre-made posts) but it does not allow any design work beyond my first step which was to add some text...

> I created text and then cannot manipulate it whatsoever.

> I wanted to add a phot but the photos I uploaded in a prior atempt at a project are only available on a separate tab, not accessible in this new project 

>> there seems to be no way to create a Library of these photos to make them accessible

Has anyone had any success making this software function for a simple design project of a Facebook post?

Alternatively I HAVE made an Adobe Spark page quite easily.