i have Enterprise 10.8.1 and want to use Collector for ArcGIS but it gives my untrusted certificate on my smartphone, so i searched for this and reached out that ESRI's said to work on smartphone apps your enterprise must have CA certificate.
then i found that to use CA your machine must be on a public Domain/IP, now i want a workaround to be able to use Collector for ArcGIS and I cannot buy a certificate or offer a public domain.
any WORKAROUND!!
my machine:
Azure VM, Server 2019 Datacenter
Easiest workaround I found was to get an ArcGIS Online account and set Collector up to use that and then link the feature datasets that are being edited back into Enterprise Portal via different methods, ie setting Portal to link to an authenticated Web service or Collaboration between Portal and AGOL.