No body on a GET request using fetch API?

Question

I am sending (rather rying to) send a GET request to my server using the native JavaScript fetch API with an HTML client. On postman I can do this, no problems, what is wrong?

Here is the error:

Unhandled Promise Rejection: TypeError: Request has method 'GET' and cannot have a body

Again, I need to make a GET request, not a post request... Postman does allow this.

Here is the code:

fetch('http://www.localhost:3000/get-data', {
    method: 'GET',
    headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
    },
    body: JSON.stringify({
        a: 1,
        story: document.getElementsByTagName("input")[0].value,
    })
});

PD: I using Safari, bur Chrome, although marking a different looking error that conveys the same message, still does not work.