This configuration ends up with one proxy_set_header directive.
location2:
name: /tc
proxy_pass: http://backend:8111/tc
proxy_http_version: 1.1
proxy_set_header: X-Forwarded-For $remote_addr
proxy_set_header: Host $host
proxy_set_header: Upgrade $http_upgrade
proxy_set_header: Connection $connection_upgrade