Hi all,
I'm new to OpenProject, doing first steps with the api.
Would like to create users through api calls, but fail and can't find examples / solutions anywhere in the web...

Got an API key, authentication works, I can get a list of existing users by GET'ing /api/v3/users, nice json list, all good.
Now I'm trying to create a user.
I'm POST'ing to /api/v3/users, but get a result code 500 and a content saying

'_content' => '{"_type":"Error","errorIdentifier":"urn:openproject-org:api:v3:errors:InternalServerError","message":"An internal error has occured. 405 Not Allowed"}'

My request is:

  DB<4> x $request
0  HTTP::Request=HASH(0x7fbba0c6b680)
   '_content' => '{ "login": "h.wurst", "email": "h.wurst@openproject.com", "firstName": "Hans", "lastName": "Wurst", "admin": true, "language": "en"}'
   '_headers' => HTTP::Headers=HASH(0x7fbba0c6b6f8)
      '::std_case' => HASH(0x7fbba0c6bfe0)
         'if-ssl-cert-subject' => 'If-SSL-Cert-Subject'
      'authorization' => 'Basic xxxxx'
      'content-length' => 132
      'content-type' => 'application/json'
      'user-agent' => 'libwww-perl/6.05'
   '_method' => 'PUT'
   '_uri' => URI::https=SCALAR(0x7fbb9ffc1f30)
      -> 'https://openproject.wawawis.com:447/api/v3/users'
   '_uri_canonical' => URI::https=SCALAR(0x7fbb9ffc1f30)
      -> REUSED_ADDRESS

, a copy & paste from the API documentation (after stripping \n\c characters).
No matter what I try, same result. I'm stuck.

If somebody please could enlighten me, I'm running out of ideas....

Thanks,
Thomas.