var url = 'http://localhost:8000/employees';

async function addEmployee() {
    try {
        let response = await fetch(url,{
            method: "post",
            body: JSON.stringify({
                id: 6,
                fullname: 'Derék László',
                city: 'Szeged',
                salary: 2150000
            }),
            headers: {
                "Content-Type": "application/json"
            }
        });
        let result = await response.json();        
        console.log(result);
    }catch (err) {
        console.log('Hiba! A dolgozó hozzáadása sikertelen!');
        console.log(err);
    }
}
addEmployee();