Lambda + Node.js layer = frustration

I have a bunch of lambdas and want to attach a layer containing several node packages. The lambda is finding the code, so I know the path is correct. I think my question is how to call a constructor within the layer from my index.mjs lambda module.

Any help much appreciated,

David

Lambda Code:

var FPDF = import('/opt/node_modules/node-fpdf/src/fpdf_js.js');

export const handler = async (event) => {

    console.log(JSON.stringify(event));
    var pdf = new FPDF('P','mm','A4');

    pdf.AddPage();
    pdf.SetFont('Arial','B',12);
    pdf.Cell(5,5,"Hello World!!");
    pdf.Output('F',`test.pdf`);
}

Code in node_modules/node-fpdf/src/fpdf_js.js:

module.exports = class FPDF {
    constructor(orientation = 'P', unit = 'mm', size = 'A4', PDFA = false, posX = 1, posY = 1) {
        ....
    }
    
    SetFont(family, style = '', size = 0) {
        ....
    }
    ....
}

I've tried the following:

import { FPDF } from '/opt/node_modules/node-fpdf/src/fpdf_js.js';

var pdf = new FPDF('P','mm','A4'); 

**SyntaxError: Named export 'FPDF' not found. The requested module '/opt/node_modules/node-fpdf/src/fpdf_js.js' is a CommonJS module, which may not support all module.exports as named exports. CommonJS modules can always be imported via the default export, for example using: import pkg from '/opt/node_modules/node-fpdf/src/fpdf_js.js'; const { FPDF } = pkg;**

import pkg from '/opt/node_modules/node-fpdf/src/fpdf_js.js';
const { FPDF } = pkg;

var pdf = new FPDF('P','mm','A4'); 

**TypeError: FPDF is not a constructor**

var FPDF = require('/opt/node_modules/node-fpdf/src/fpdf_js.js');

var pdf = new FPDF('P','mm','A4'); 

**require is not defined in ES module scope, you can use import instead**

var FPDF = import('/opt/node_modules/node-fpdf/src/fpdf_js.js').FPDF;

var pdf = new FPDF('P','mm','A4'); 

**TypeError: FPDF is not a constructor**

var FPDF = import('/opt/node_modules/node-fpdf/src/fpdf_js.js').default();

var pdf = new FPDF('P','mm','A4');

**ImportCall("/opt/node_modules/node-fpdf/src/fpdf_js.js").default is not a function**