I looked again into the TopPagesByActions and as it seems to be quite simple, I tried migrating it to Matomo 3.
You can try out my version from here:
(e.g. by downloading https://github.com/Findus23/piwik-top-pages-by-actions/archive/master.zip and moving the folder in the zip to plugins/TopPagesByActions)
While the User Interface is quite outdated and a bit buggy, that shouldn’t affect you as it is only fetching the API.
http://localhost/piwik/index.php?module=API&method=TopPagesByActions.getTopPagesByActions&idSite=1&lastMinutes=60&format=JSON&token_auth=anonymous returns the following:
[
{
"number": "17",
"idaction_url": "5761",
"time": "0.00000000",
"idaction_name": null,
"name": "null",
"url": "http://localhost/piwik-1.9.3-b10.zip"
},
{
"number": "16",
"idaction_url": null,
"time": "0.00000000",
"idaction_name": "9",
"name": "non",
"url": "null"
},
{
"number": "10",
"idaction_url": "5730",
"time": "1.67167000",
"idaction_name": null,
"name": "null",
"url": "http://localhost/latest.zip"
}
]