Is this an owner build? The reason I ask is the manufacturer of the shell will have specific instructions on the proper concrete collar, backfill, etc., and all that will allow for a nice coping.
My FB shell does have that edge, and the concrete collar is poured around the shell, and then up to the lip. My coping is glued to the FB shell, as well as the concrete around the shell, then pavers on top of the base around. Here is a few pics I have of the base on top of the concrete, before the next batch of concrete is poured around the shell.
An my paver coping on top...

Note the rail for my autocover is also there, but the coping sits on top of the shell.