Download a build: no response

[Qingcheng0077]

Hi,
I edited the conifg.js file for supporting our custom device, for instance:
{ name: "abc", model: "xyz", },
accordingly in public\releases\index.json I added followed download path:
"xyz": [ { "version": "11.5.0", "variant": "minimal", "url": "path/to/the/zipfile_1/on/server" }, { "version": "11.5.0", "variant": "gapps", "url": "path/to/the/zipfile_2/on/server" } ]

unfortunately the download page hangs:
App running at:

• Local: http://localhost:8080/
  
  and I can't see the public\releases\index.json is called anywhere...
  

it´s same if I use the original public\releases\index.json file.

Could someone here help me? thanks in advance!