[The similar questions are related to other devices and I don't intend to do factory reset.]
I cannot see what is being 'shown' on the screen, only interact through fastboot or randomly touching the screen. The wifi is also working.
If I could enable debugging, I could use scrcpy to see and interact using mouse on a linux computer.
I suppose I can use fastboot to root/unlock/install apps. But I have no experience doing that. The only command I succeeded was this:
fastboot -s H7AZCY5468078HN oem device-info ... (bootloader) Device tampered: false (bootloader) Device unlocked: false (bootloader) Device critical unlocked: false (bootloader) Charger screen enabled: false (bootloader) Display panel: (bootloader) Sysconf ssn: H7AZCY5468078HN (bootloader) Sysconf adb enable: 0 (bootloader) Sysconf reboot reason: 0 (bootloader) Sysconf isn: N0CZ1738MB0033372 OKAY [ 0.110s] finished. total time: 0.110s
Also, touch-guessing until enabling debug seems impossible in practice.
ps. My ASUS Zenfone Selfie Pro 4 graphics chip burned and the screen is completely blank after boot.