I am using following API url to post the data in BC from postman- 
https://api.businesscentral.dynamics.com/v1.0/XXXXX/Sandbox/ODataV4/Company('CRONUS%20DE')/Kontakte
masked the XXXXX which was company guid
For GET call I am able to get List of all contact available in environment.
but for POST its throwing error- 
{
 "error": {
 "code": "BadRequest_MethodNotAllowed",
 "message": "Entity does not support insert."
}
}
any help will be appreciated