Applying this example from the documentation to the server accessible to me does not work.
<?xml version="1.0"?>
<ocs>
<meta>
<status>failure</status>
<statuscode>997</statuscode>
<message>Current user is not logged in</message>
<totalitems></totalitems>
<itemsperpage></itemsperpage>
</meta>
<data/>
</ocs>
Getting this response, no matter which account credentials are used, including users with administrator rights.
They don’t have MFA enabled.
I also researched all topics on this forum & search engine findings on this error & all the results were useless, because they were related to some weird authentication and/or user setup. In this case, there’s a standard Nextcloud installation with barely any apps installed.