$.ajax({
    type: 'GET',
    url: myapi.myapi_url + '/posts',
    beforeSend:function(xhr){
        xhr.setRequestHeader('X-WP-Nonce', myapi.nonce);
    },
    data: {
        post_type: params.post_type
    },
    success:function(data){
        console.log(data);
    },
    error:function(data){
        console.log(data);
    }
});