Unable to get Function / Probe working

I am trying to create a function / probe but just not getting any results. The function is suppose to report the interface utilization.

Below is the Function “In-Utilization” code:

if(oid("1.3.6.1.2.1.31.1.1.1.6.13"),round(rate(diff64(oid("1.3.6.1.2.1.31.1.1.1.6.13"))*8)),-1)

Then on device, in appearance I have the following, but it is only displaying the function name. If I go into device settings in Dude, under SNMP tab I can see all the interfaces and values, which tells me SNMP is working, but for the life of me, I cant get the values via a Function. Dude is 6.46.8 long term

test: [In-Utilization()]

Will really appreciate if someone can guide me here, as I have pulled out 1 of the 2 hairs I have left

Solved, seems it does not like the “-” in the function name