Adamantine Armor Crit negation

[MartianXi]

Is there a way/effect to negate the Crit damage following a Nat 20 roll for those immune to critical hits.

I’ve just been burning the roll by rolling the attack again to clear the crit but would be nice to have it automatic.

[Zacchaeus]

Yes, add an effect of IMMUNE: critical to the player's actions tab. More in these videos https://www.fantasygrounds.com/forums/showthread.php?41478-Effects-Videos-for-5E

And on the Wiki https://fantasygroundsunity.atlassian.net/wiki/spaces/FGCP/pages/996642031/5E+Effects+for+Advanced+Automation