So like ik how to make a national spirit and for it to appear in game but idk how to give a modifier to it. Like for example how would i make a national spirit with -10% stability and 0.02 daily fascism support for example? It would be much appreciated if you can help me with this!

come to your "modifier" section on the national spirit and add this;

add_stability = -0.1

fascism_drift = 0.02