input: Write a python function to send a POST request to a specified URL with given data and return the response text.
  assert send_post_request('https://example.com/api/submit', {'message': 'Hello!', 'name': 'John'}) == 'Success'
  assert send_post_request('https://example.com/api/submit', {'message': 'Hi!', 'name': 'Alice'}) == 'Received'
  assert send_post_request('https://example.com/api/submit', {'message': 'Goodbye!', 'name': 'Bob'}) == 'Farewell'
output: import requests
  
  def send_post_request(url, data):
      response = requests.post(url, json=data)
      return response.text