POST database relation in strapi

Question

I have a strapi project and A flights has somr relations like drones, pilots. For example if we using postman to get a flight i send :

{

"data" : {
   "Duration" : "10",
   "Address" : "Address",
    "account": 1,
    "drone": "1",
    "pilot": 1,
    "User": 1,
    "zone": 1,

} }

the response is :

{
      "id": 25,
       "Duration" : "10",
       "Address" : "Address",
        "account": 1,
        "drone": "1",
        "pilot": 1,
        "User": {
          "id": 1,
          "username": "AhmedMedhat",
          "email": "[email protected]",
          "provider": "local",
          "password": "$2a$10$8tkwcp73AbE0aylQyOsIdefgSiuaoOcPJzbZWxk9W2IN85SghOIjO",
          "resetPasswordToken": null,
          "confirmationToken": null,
          "confirmed": false,
          "blocked": false,
          "createdAt": "2022-11-03T06:32:57.225Z",
          "updatedAt": "2022-11-03T06:35:05.902Z"
      },
        "zone": 1,
   }

only the user is populated successfully but the other relations always return null .. maybe bec user is plugin and others is api i don't know, it works in the strapi built in routes but my customized one doesn't work .. can anyone help ??