Add the highlighted nodes shown in the image below, location at the top of the image.

In the below image to add the Amount pin to the Set Memebers node in the images below select the node and tick on amount in the details panel.

Then Add the highlighted nodes and there connected nodes shown in the image below, location at the top of the image.

Next create a new local variable called Stack Added L and set it to an Integer. You can add Local variables in the my blueprint panel under where normal variables are added.

Add the highlighted nodes shown in the images below, location at the top of the images.