        const iv = document.getElementById('iv').value;

            const requestData = {
                action: action,
                data: data
            };

            if (action === 'des_encrypt') {
                requestData.key = key;
                requestData.iv = iv;
            }

            fetch('http://localhost:8051', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json'
                },
                body: JSON.string