Hi,
This is a Google URL. Its not really usefull to try to understand how their API provide it.
In the meanwhile, you can set mime type from the server to say : hey client, with the route, i will serve you a content with this type : You should check out this wikipedia article: https://en.wikipedia.org/wiki/Media_type or better mdn article : developer.mozilla.org/en-US/docs/Web/Security/Sec…
Cheers !