Reference form fields by ID

[turbo2ltr]

I have a PDF that I'm trying to fill that is not my PDF. I dumped out all the names using form.acroForm.getAllFields() and found that some fields return "undefined" and several fields share the same name. I've only been able to update the field value using form.getTextField('some name').setText(). But how do I set the field value for the fields that have an undefined or ambiguous name?
Is there a way to set the value based on the ID?

This was what I dumped out of the acroForm field list. The ID is from allfields[x][1].objectNumber, the name is from the dict map containing the value "/TU" which I have no idea if that is correct but seems to work.

453: Description
454: Location
455: From
456: To
457: Time
458: To
459: Supervisor
460: Phone
461: undefined
462: undefined
463: Cell
464: undefined
465: undefined
466: Point-of-Contact Information
467: Phone
468: undefined
469: undefined
470: Uniform
471: Number Required
473: ID Number_1
474: Name \(indicate if on special assignment such as bike or horse patrol\)_1
475: Signature_1
476: Time On_1
477: Time Off_1
478: Two-way Travel Time_1
479: Total Hours_1
480: ID Number_2
481 - 569 (repeating table entries like 473 to 479)
570: Total Hours_14

Code..

        const response = await fetch(url);
        if (!response.ok) {
            console.log(`HTTP error! Status: ${response.status}`);
        }
        const blob = await response.blob();
        const arrayBuffer = await new Response(blob).arrayBuffer();
        const byteArray = new Uint8Array(arrayBuffer);
        const pdfDoc = await PDFLib.PDFDocument.load(byteArray);
        const form = pdfDoc.getForm();
        const allfields = form.acroForm.getAllFields();

        for(var x=0;x<allfields.length;x++) {
            var obnum = allfields[x][1].objectNumber.toString();
            allfields[x][0].dict.dict.forEach(function(value, key) {
                if(key.toString() == "/TU") {
                    console.log(obnum + ": " + value.asString());
                }
            });
        }

[turbo2ltr]

Ok think I figured it out. I poked (more) around the source and found PDFAcroField.getFullyQualifiedName() and that puts out more unique names.