How to output nodejs post request body?

Question

Node.js

I am using Koa.
There are post requests that come from a third-party service. Send json.
All are perfectly processed, except for one request. For example, this is how I check the content of the request:

router.post('/myevent', async (ctx, next) => {
  let body = ctx.request.body;
  console.log(body); 
  ctx.body = body;
});

Perfectly displays the same sent json to the console.
But one request for some reason displays an empty object `{}`.
The service that sends requests will assure that everything is ok .. I
started looking at the headers that come. Here they are on those requests that are perfectly processed:

{ method: 'POST',
  url: '/myevent',
  header: 
   { host: 'mydomain.ru',
     connection: 'close',
     'content-length': '84584',
     'user-agent': 'GuzzleHttp/6.3.3 curl/7.65.0 PHP/7.3.9',
     'content-type': 'application/json' } }

It is perfectly visible that the content-type is the same json, content-length is excellent. And in the console I see what I need!
And here is the request with an empty object:

{ method: 'POST',
  url: '/myevent',
  header: 
   { host: 'mydomain.ru',
     connection: 'close',
     'content-length': '6335',
     'user-agent': 'GuzzleHttp/6.3.3 curl/7.65.0 PHP/7.3.9' } }

As you can see, there is no `content-type` and `content-length` is much smaller.
From the side of the service, they assure that since the content-length has a certain value, then they send the request perfectly. And I take something clumsily. But how can I process it? All that can be tried, displays an empty object.
Request processing is the same for all, (code above). What can you try?
Thank you.

Answer 1

It's about content-type , say to set it to 'application/json' .
It defaults to text .
Or handle both options - with json and with text