Termination Life event fast formula is not working out

We have configured a termination life event to trigger upon entering the actual termination date in the per_periods_of_service table. Below is a basic Fast Formula created based on Oracle docs; however, it is not functioning as expected.

inputs are BEN_ASG_IN_ACTION_CODE (TEXT)
l_create_ptnl = 'N'
If BEN_ASG_IN_ACTION_CODE ='TERMINATION' or BEN_ASG_IN_ACTION_CODE ='INVOLUNTARY_TERMINATION'
THEN (l_create_ptnl = 'Y')
return l_create_ptnl

Kindly help me to understand where the issue is? Also, if anyone has a Fast Formula for triggering termination, kindly share it.

Thanks in advance