empty body with post method

[xdien]

I am building a backend for esp8266 device. All working fine from socketio to frontend.
I implement an API that stores device activity log, it receives data directly from esp8266 with ESP8266HTTPClient library. But in API only get an empty body.
That API works fine with curl.
Well, I tested it with another API post on the internet, but the ESP8266HTTPClient library works fine
http://ptsv2.com/t/zecae-1639725292/d/6406368634339328/text

• Create model, repository, controller from lb4 command.
  Below is the controller snippet :

import {
  repository
} from '@loopback/repository';
import {
  getModelSchemaRef, post, requestBody,
  response
} from '@loopback/rest';
import {SensorActivityLog} from '../models';
import {SensorActivityLogRepository} from '../repositories';

export class SensorActivityLogController {
  constructor(
    @repository(SensorActivityLogRepository)
    public sensorActivityLogRepository: SensorActivityLogRepository,
  ) { }

  @post('/sensor-activity-logs')
  @response(200, {
    description: 'SensorActivityLog model instance',
    content: {'application/json': {schema: getModelSchemaRef(SensorActivityLog)}},
  })
  async create(
    @requestBody({
      content: {
        'application/json': {
          schema: getModelSchemaRef(SensorActivityLog, {
            title: 'NewSensorActivityLog',
            exclude: ['sensorid'],
          }),
        },
      },
    })
    sensorActivityLog: Omit<SensorActivityLog, 'sensorid'>,
  ): Promise<SensorActivityLog> {
    console.log("body ", sensorActivityLog);
    return this.sensorActivityLogRepository.create(sensorActivityLog);
  }
}

• Command to run the backend
  npm run clean; npm start
  

Anyone have the same situation as me? please share with me

[xdien]

Problem solved by adding header

• "Content-Type":"application/json"
• "Accept":"application/json"