Hi... I have this record added by the Electronic Invoice bundle It is included as a sublist subrecord under customers sublist ID is

recmachcustrecord_psg_ei_email_recipient_cust

I am trying to add a row to it using suitescript but I keep getting this error

{"type":"error.SuiteScriptError","name":"FIELD_1_IS_NOT_A_SUBRECORD_FIELD","message":"Field custrecord_psg_ei_email_recipient_cust is not a subrecord field.","id":.......

This is my code

let recipient = context.newRecord.getSublistSubrecord({
  sublistId: "recmachcustrecord_psg_ei_email_recipient_cust",
  fieldId: "custrecord_psg_ei_email_recipient_cont",
  line: 0,
});

I tried other IDs but nothing worked Any easy way to know what is the ID of the field that holds the subrecord? Do I understand this correctly?

there is no such thing as a custom subrecord

The parent is the Customer record.

your screenshot is of a custom record

Yeah

you will never access it as a subrecord

Isn't the subrecord just a child record that could be custom or standard?

thats not what a subrecord is

Hmm, I will read more about it then.

SuiteScript 2.x Scripting Subrecords is the usual starting place to learn about subrecords

Thanks 🙏