S-OFF question

Sir, to make s off i need to flash TW recovery ? When i tried to did it , show me this log

1. Checking phone connectivity.......
Phone connection confirmed!
HTC KEY CARD VERSION: 7
2. Checking Server connectivity...
Server connection confirmed!
3. Checking PowerAdapter connectivity...
PowerAdapter connected, processing request to adapter...
Process started
Starting operation...
Sending oem writesecureflag 0
... (bootloader) HTC KEY CARD VERSION: 7
FAILPERMISSION DENY (DENY)
FAILED (remote: PERMISSION DENY (DENY))
Execution time is 15(ms)
Operation completed!
Releasing adapter.
Request completed

My phone is HTC U11 Life, first i tried in 7.1, then upgrade to Oreo, and it´s the same message. S OFF in U11 Life is possible?
Thanks in advanced
B.R.