http_post not working while http_get is fine

  select content::json->>'allowed'
  from http_get('https://jsonplaceholder.typicode.com/todos/1');

  select content::json->>'allowed'
  from http_post('https://jsonplaceholder.typicode.com/todos/1',
    jsonb_build_object('test', 'test')
  );

hint: "No function matches the given name and argument types. You might need to add explicit type casts."

message: "function http_post(unknown, jsonb) does not exist"