Question: How do I add a trusted proxy host IP to my on premise instance?

Answer: You can set a trusted proxy IP on a per instance basis. This is done in the following config file with INSTANCE replaced with your helpdesk's instance name:

/opt/deskpro/data/instances/INSTANCE/services/deskpro/config/deskpro-config.php
 copy

If you scroll through the file you will have the following entry:

//######################################################################
// env
//######################################################################

$CONFIG['env'] = [
  'set_umask' => 0000,
  'environment' => 'prod',
  'debug_mode' => false,
];

// If requests are coming from a NB or proxy,
// you must specify the host(s) here so
//$CONFIG['env']['trust_proxy_data'] = [
//  '0.0.0.0/0'
//];

$CONFIG['env']['trust_proxy_data'] = [
  '127.0.0.0/8',
  '172.24.0.0/16',

];
 copy

You can additonal IPs to the configuration here.