Swagger-ui keeps showing example petstore instead of provided swagger.json

I followed instructions to set up swagger documentation for my existing node API using swagger-jsdoc. The swagger.json is being served correctly and I added a path to it in the url parameter of the SwaggerUiBundle in index.html like this:

const ui = SwaggerUIBundle({
url: "https://my.domain:5292/swagger.json",
dom_id: '#swagger-ui',
presets: [
  SwaggerUIBundle.presets.apis,
  SwaggerUIStandalonePreset
],
plugins: [
  SwaggerUIBundle.plugins.DownloadUrl
],
layout: "StandaloneLayout" })

However, the first thing it tries to do when opening the page in the browser is showing the default http://petstore.swagger.io/v2/swagger.json instead of my swagger.json. It actually fails to do so because I'm serving the page through https and the petstore is not https but that's a different matter...

Inputing my address to the swagger.json manually into the form on the page works as expected. It shows the API page correctly and validates it. However, I don't want to always re-enter the address there and would like to have it as a default.

via md2312