I need a little help with curl

[tuxap]

I'm trying to send using curl but it always returns the same error:

{"message":"Could not bind JSON","success":false}

syntax:
curl -v -H "Content-Type:application/json" -H "Accept: application/json" -X POST -d '{"group":"tuxap","username":"andre","location":"tracking","time":1519175332,"wifi-fingerprint":[{"mac":"9a:de:d0:f6:b7:54","rssi":-49},{"mac":"9e:de:d0:f6:b7:54","rssi":-45},{"mac":"e4:18:6b:3b:b1:64","rssi":-65}]}' http://ml2.internalpositioning.com/track

POST /track HTTP/1.1
Host: ml2.internalpositioning.com
User-Agent: curl/7.58.0
Content-Type:application/json
Accept: application/json
Content-Length: 294

< HTTP/1.1 400 Bad Request
< Access-Control-Allow-Credentials: true
< Access-Control-Allow-Headers: Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, X-Max
< Access-Control-Allow-Methods: GET
< Access-Control-Allow-Origin: *
< Access-Control-Max-Age: 86400
< Content-Length: 49
< Content-Type: application/json
< Date: Wed, 21 Feb 2018 00:59:57 GMT
< Server: Caddy

Thank you

[schollz]

ml2 is down. Try using https://ml.internalpositioning.com/track