Отправка POST запроса React Native

Помогите разобраться c отправкой POST запроса из формы. Я только начал изучать React Native, сильно не пинайте за код. Вот что есть сейчас:

import { StatusBar } from 'expo-status-bar';
import React, { useEffect, useCallback } from 'react';
import { SafeAreaView, StyleSheet, Text, View, TextInput, Button, Alert } from 'react-native';
import { useForm, Controller } from "react-hook-form";

export const NewTransactions = props => {
  
  const { register, handleSubmit, setValue } = useForm();
  const onSubmit = useCallback(formData => {
    
    
    fetch('url',{
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',

      },
      body: JSON.stringify({ 
        formData

      })
      }).then(response=>response.json() )
      
    
     console.log(formData);
    

  }, []);
  const onChangeField = useCallback(
    name => text => {
      setValue(name, text);
    },
    []
  );
    
  useEffect(() => {
    register('category');
    register('count');
    register('date');
    register('comment');
    register('type');
  }, [register]);
  
  return (
    <SafeAreaView style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
      <TextInput
        autoCompleteType="off"
        keyboardType="default"
        textContentType="none"
        placeholder="Категория"
        onChangeText={onChangeField('category')}
      />
      <TextInput
        autoCompleteType="off"
        keyboardType="decimal-pad"
        textContentType="none"
        placeholder="Сумма"
        onChangeText={onChangeField('count')}
      />
      <TextInput
        autoCompleteType="off"
        keyboardType="default"
        textContentType="none"
        placeholder="Дата"
        onChangeText={onChangeField('date')}
      />
      <TextInput
        autoCompleteType="off"
        keyboardType="default"
        textContentType="none"
        placeholder="Комментарий"
        onChangeText={onChangeField('comment')}
      />
      <TextInput
        autoCompleteType="off"
        keyboardType="default"
        textContentType="none"
        placeholder="Тип транзакции"
        onChangeText={onChangeField('type')}
      />
      <Button title="Сохранить" onPress={handleSubmit(onSubmit)} />
    </SafeAreaView>
  );
};

В ответ я получаю ошибку

[Unhandled promise rejection: SyntaxError: JSON Parse error: Unable to parse JSON string]
at [native code]:null in parse
at node_modules\react-native\node_modules\promise\setimmediate\core.js:37:13 in tryCallOne
at node_modules\react-native\node_modules\promise\setimmediate\core.js:123:24 in setImmediate$argument_0
at node_modules\react-native\Libraries\Core\Timers\JSTimers.js:130:14 in _callTimer
at node_modules\react-native\Libraries\Core\Timers\JSTimers.js:181:14 in _callImmediatesPass
at node_modules\react-native\Libraries\Core\Timers\JSTimers.js:441:30 in callImmediates
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:387:6 in __callImmediates
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:135:6 in __guard$argument_0
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:364:10 in __guard
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:134:4 in flushedQueue
at [native code]:null in flushedQueue
at [native code]:null in invokeCallbackAndReturnFlushedQueue

На сервере куда отправляется запрос все работает. Проверял PostMan`ом