So I have a 2019 MacBook Pro that I had to wipe the hard drive on. Security Utility won't let me boot to external usb installer. When opening Security Utility in Recovery Mode it informs me that no admin account was found. If I try to reinstall OS from recovery it says that it can't contact the server.
MacBook Pro (2017 – 2020)
If you have a 2019 model, then you will not be able to boot from USB until you have installed & configured an OS on the laptop since the T2 security chip must be able to authenticate a valid macOS admin user account. Your only option at this point is to reinstall macOS through Internet Recovery Mode. Try using Command + Option + R to access Internet Recovery Mode to access the most recent online macOS installer which at this time is macOS 14.x Sonoma.
The "The recovery server could not be contacted" error has been reported by users for months now for accessing older versions of macOS, but I wasn't sure if it was based on OS or just on older Obsolete hardware, but your laptop suggests it is OS based. I would suggest providing Apple with product feedback here making sure to mention your 2018 laptop model since it is still fully supported hardware (or is supposed to be anyway).
If you still have trouble with Internet Recovery Mode for Sonoma, then you may need to perform a firmware "Restore" followed by another attempt at Internet Recovery Mode using Command + Option + R.
Keep this in mind if you ever decide to repair your laptop since one day you may be unable to use Internet Recovery Mode at all to reinstall macOS once this laptop becomes Obsolete.
2019 MacBook Pro Security Utility, No admin account
