I am new to JS and facing a problem using cytoscape.js I want to get data from a PG database and based on that create nodes. However, no nondes are being shown. In the following is my code. Does anyone have any tips? Many thanks!

window.addEventListener("DOMContentLoaded", my_function);
var data = [];
let pg = import('./pg.js')
let nodes = pg.my_nodes
for (node in nodes){
  if (node !== undefined && node !== []){
    data.push(node)
  }
}

function my_function() {
  var cy = (window.cy = cytoscape({
      container: document.getElementById("cy"),
      style: [{
          selector: "node",
          style: {
            content: "data(id)"
          }
        },
        {
          selector: "edge",
          style: {
            "curve-style": "bezier",
            "target-arrow-shape": "triangle"
          }
        }
      ],
      elements: {
        nodes: data, 
        edges: []
      },
      layout: {
        name: "grid"
      }
    }));