NPC attack and damage macro (roll20 OGL 5e sheet)

So we are using an adapted version of the official roll20 OGL sheet for Arcanis 5e. Last night was our first game, I bumped into an issue I hope you call all help me won’t with. are there any NPC attack & damage macros that also roll crit damage when there is a crit? I have some simple macros on all my tokens but all they do is roll attacks. Instead of attack and damage. 

This is an option settings tab on the D&D 5th Edition by Roll20 sheet. You could look and see how it was done there. The basic technique is to roll all possible dice that may be needed, and use a roll template to only show the actual dice that were used. This technique is baked into the official sheets roll template code.

To add to Keith's answer, the NPC Action template from the D&D 5e OGL Roll Templates should work well for OP, as it rolls both the attack and the damage (including critical damage if applicable) simultaneously. 

thanks!