How to receive integer array by recvfrom ?

Question

Dear
from arduino:

Code:

int8_t payload[] = { '5','6'};

in X2e Gateway

Code:

rx_data_ep, rx_addr_ep = sd.recvfrom(8192,MSG_DONTWAIT)

it easy to receive and display; but
how can I do to send

Code:

int8_t payload[] = { 5, 6};

Best regards.