Hello everyone,
I am trying to model an orthotropic material using the MAT9OR card.
From the Help page for this material card, I can see that NU31 can be interpreted as NU13, through the SYSSETTING.

I tried to create a SYSSETTING card to switch the NU31 field to NU13, however, I cannot find the correct option to choose:

I referred back to the Help page for SYSSETTING, where MAT9OR is indeed listed as an option:

I just cannot find it in my interface.
If anyone knows what I'm doing wrong, please let me know.
Thanks,
Martina