kumomta/docs/reference/events/get_egress_path_config.md

kumo.on('get_egress_path_config', function(domain, egress_source, site_name))

!!! note This event handler is in flux and may change significantly

Not the final form of this API, but this is currently how we retrieve configuration used when making outbound connections

kumo.on('get_egress_path_config', function(domain, egress_source, site_name)
  return kumo.make_egress_path {
    enable_tls = 'OpportunisticInsecure',
  }
end)

See also kumo.make_egress_path.