Error when using setFontSize on PDFTextField within a form: "No /DA (default appearance) entry found for field"

[Trekiros]

Hi,

Does anybody have an example of a form text field where you have successfully changed the font size? I have tried this:

const pdfDoc = await PDFDocument.load(...)

const form = pdfDoc.getForm()

const font = await pdfDoc.embedFont(StandardFonts.Helvetica)

const descriptionField = form.createTextField('description')

descriptionField.setFontSize(10) // Error here

descriptionField.addToPage(page1, { x: 130, y: 565, width: 140, height: 30, borderWidth: 0 })

However, I get the following error message on setFontSize on runtime:
Error: No /DA (default appearance) entry found for field: description

I have tried a bunch of different fixes (one of them inspired by another discussion, where the poster left saying they found a solution, but didn't share a code sample of it... always love to see it).

// Everything I've tried (none of them had any effect):
// Each of them was added, individually, then together, just before descriptionField.setFontSize(10)
// I also tried having the last one, without descriptionField.setFontSize(10), to see what it'd do - there were no errors, but the font size remained the default value instead of becoming 10.
descriptionField.defaultUpdateAppearances(font)
form.updateFieldAppearances(font)
descriptionField.updateAppearances(font, (textField, widget, font) => {
    return drawTextField({
        font: font.name,
        fontSize: 10,
        x: 130 + j * xOffset,
        y: 565 - i * yOffset,
        borderColor: rgb(0,0,0),
        borderWidth: 0,
        color: rgb(0,0,0),
        height: 30,
        padding: 0,
        textColor: rgb(0,0,0),
        width: 140,
        textLines: (textField.getText() || '').split("\n").map((line, lineNumber) => ({
            x: 130
            y: 565 - lineNumber * 10,
            encoded: new PDFHexString(line)
        })),
    })
})

I haven't been able to find anything in the docs or using AI to fix this. My goal is simply to create a multi-line text field.
Maybe even one that automatically re-sizes the font based on how much text the input field contains - but I'll settle for just having an input field where the font doesn't scale to the height of the input.