React native cli formdata is sending data in a object it should not be in any object and array

Question

im trying to post data using formdata but formdata sending data in a object..it should not be in any object or array,,in Reactjs web its working fine it just send like this lab_id : 1 ..how can i solve this issue ..please let me know what can i do,,,

//data is sending like this

{"_parts" : [[
        ['date', current_date],
        ['test_ids[]', tests_data],
        ['lab_partner_id', lab_id],
        ['booking_for', selectedMember],
        ['time', time_slot],

        ['health_package_id', health_packages_details],

        ['payment_mode', payment_mode],
      ]]},

// it should be like this only

health_package_id: health_packages_details

//my code

const onPay = async (
current_date,

tests_data,
lab_id,
selectedMember,
time_slot,
health_packages_details,
payment_mode,
) => {
const token = await AsyncStorage.getItem('userToken');
dispatch(startSubmitting());
const url = `/auth/make-booking`;

let  formdata = new FormData();
formdata.append('lab_partner_id', lab_id);
formdata.append('booking_for', selectedMember);
formdata.append('date', current_date);
formdata.append('time', time_slot);

health_packages_details &&
  formdata.append('health_package_id', health_packages_details);
  tests_data && formdata.append('test_ids[]', tests_data);
formdata.append("payment_mode", payment_mode);

 
const response = await api
  
  .post(
    url, formdata , 
    
    {
      headers: {
        Authorization: `Bearer ${token}`,
         
      },
    },
  )

  .then(res => {
     console.log("res hhh", res);
      if (res.data.payment_mode == "ONLINE") {
        initiatePaymentInterface(res.data);
     }
    dispatch({
      type: 'BOOKING',
      payload: response,
    });
    setLoading(false);
    initiatePaymentInterface(res.data);
     
    return res;
  })
  .catch(error => {
      actions.setErrors(error.response.data.error);
    failedPaymentInitiate(error.response);
    setLoading(false);
    
  });
 
dispatch(stopSubmitting());

};