How can I get the field ID of a Workfront Planning field?

[karinasaijo]

Dear community,

I'm trying to create an external look up field for the Workfront Planning API, and in the instructions it says that I should add:

• JSON Path: $.records[*].data.{fieldID}

  {fieldID} is the field to display in the External lookup search results on the custom form for end users.

Can anyone help me understand what is exactly the fieldID? Is it the WF Planning field ID? If so, how can I get it? I was not able to find it.

Thanks in advance!