PUT request /rest/api/2/mypreferences?key=jira.user.locale using a JSON payload

Hi,

Is there any way to make a put request to /rest/api/2/mypreferences?key=jira.user.locale using a JSON payload. It clearly works using a simple text e.g. en_US but the content type is application/json and it should make sense also the payload to be JSON.

Thanks