nginx-proxy-manager/src/backend/templates/stream.conf

# {{ incoming_port }} TCP: {{ tcp_forwarding }} UDP: {{ udp_forwarding }}

{% if tcp_forwarding == 1 or tcp_forwarding == true -%}
server {
    listen {{ incoming_port }};
    proxy_pass {{ forward_ip }}:{{ forwarding_port }};
}
{% endif %}
{% if udp_forwarding == 1 or udp_forwarding == true %}
server {
    listen {{ incoming_port }} udp;
    proxy_pass {{ forward_ip }}:{{ forwarding_port }};
}
{% endif %}