selectedIndex by buttonId

Question:
Good morning,
I am on the end of my knowledge. I need simply thing - I have a button on site of my website and need open lightbox with preselected dropdown field. I need solve this in velo because I want more buttons with linked dropdown item.

I have a code in rosegoldlook.eu/dokonaly-makeup:

import wixWindow from 'wix-window';

$w.onReady(function () {
  $w('#btnpoptat01').onClick(function () {
    let dataObj = {
      "source": "btnpoptat01"
    };
    wixWindow.openLightbox("poptavka-popup", dataObj);
  });
});

And code in lightbox with fields:

import wixWindow from 'wix-window';

$w.onReady(function () {
  let dataObj = wixWindow.lightbox.getContext().data;

  if (dataObj && dataObj.source === "btnpoptat01") {
    $w("#dropdown1").selectedIndex = 6;
  }
});

In past I wanted select item by option value, but for now I need simply set item by sorting.

Thank you very much!

Product:
Wix editor in developer mode (velo).

Can you clarify what you’re trying to achieve here? If you need paid help to modify existing code then you might also want to try the marketplace: https://www.wix.com/marketplace

I am trying solve one small and maybe unimportant thing.

Thank you very much. I will try it.