Google's ampUrls:batchGet returns 404? - google-api

Question

We've built back in 2017 or so a scheduled script that tests bunch of URIs against Google's AMP validation API.
Haven't checked the script in ages, but recently one of our users complained that none of the URIs list AMP equivalents (the reason we used the API for, to look up AMP versions of the pages).
Now, looking at Google's documentation and testing our JSON payload with the embedded test panel there, everything works.
But when doing the same data from our servers against the API endpoint they list, we get 404 error. Actually, just copy/pasteing the API endpoint URI to a browser returns 404, too, which is kinda unexpected.
Is there something we're missing or has Google simply shut down the service, without notifying on their documentation page about it, or..?
I am simply posting basic JSON payload with URIs that I want to check if they have AMP version available, as, for example, this:
{
"urls": [
"https://www.dailymail.co.uk/sport/football/article-6729017/Is-VAR-working-change-Reporters-analyse-video-technology-football.html?ns_mchannel=rss&ns_campaign=1490&ito=1490",
"https://www.talouselama.fi/uutiset/te/2223797c-6be5-3be1-b1aa-f774ff23d63e","https://www.theguardian.com/uk-news/2019/feb/21/teenager-shot-in-fight-on-london-tube-barking-hammersmith-and-city-line"
],
"lookupStrategy": "FETCH_LIVE_DOC"
}
to:
https://acceleratedmobilepageurl.googleapis.com/v1/ampUrls:batchGet
with POST, having service key as the query parameter (?key=xxx).
Whats we get in return, is 404. No errors, no JSON data, just plain old HTML formatted 404.

Answer 1

The service is fine and your query should return:
{
"ampUrls": [
{
"originalUrl": "https://www.theguardian.com/uk-news/2019/feb/21/teenager-shot-in-fight-on-london-tube-barking-hammersmith-and-city-line",
"ampUrl": "https://amp.theguardian.com/uk-news/2019/feb/21/teenager-shot-in-fight-on-london-tube-barking-hammersmith-and-city-line",
"cdnAmpUrl": "https://amp-theguardian-com.cdn.ampproject.org/c/s/amp.theguardian.com/uk-news/2019/feb/21/teenager-shot-in-fight-on-london-tube-barking-hammersmith-and-city-line"
},
{
"originalUrl": "https://www.dailymail.co.uk/sport/football/article-6729017/Is-VAR-working-change-Reporters-analyse-video-technology-football.html?ns_mchannel=rss&ns_campaign=1490&ito=1490",
"ampUrl": "https://www.dailymail.co.uk/sport/football/article-6729017/amp/Is-VAR-working-change-Reporters-analyse-video-technology-football.html",
"cdnAmpUrl": "https://www-dailymail-co-uk.cdn.ampproject.org/c/s/www.dailymail.co.uk/sport/football/article-6729017/amp/Is-VAR-working-change-Reporters-analyse-video-technology-football.html"
}
],
"urlErrors": [
{
"errorCode": "NO_AMP_URL",
"errorMessage": "No AMP URL for the request URL.",
"originalUrl": "https://www.talouselama.fi/uutiset/te/2223797c-6be5-3be1-b1aa-f774ff23d63e"
}
]
}