Error 6976 - STRESS label is missing on FATPARM card

Hello community, I am trying to implement a fatigue analysis for my master thesis. I tried to follow the tutorial on uniaxial S-N fatigue reported in the attached pdf.

I opened the "3.6_SN_SPRING_LINK" model and followed all the steps mentioned in the tutorial, yet the solver gives me: error n. 6976 - STRESS label is missing on FATPARM card. I can't figure out what is causing this error.

I would really appreciate if anyone could help me, thanks in advance!