JMeter: How to send request with content type header?

How can we change content type in request header of http request for restful web services? From where do we exactly change it?

Where do I put Content-Type in JMeter?

JMeter now supports multiple Header Managers. The header entries are merged to form the list for the sampler. If an entry to be merged matches an existing header name, it replaces the previous entry. This allows one to set up a default set of headers, and apply adjustments to particular samplers.

Is Content-Type a request header?

The Content-Type header is used in web requests to indicate what type of media or resource is being used in the request or response. When you send data in a request such as PUT or POST, you pass the Content-Type header to tell the server what type of data it is receiving.

Add HTTP Header Manager and add your desired header there:

Header Manager with Content-Type header