P10 Lite unlocked with EMUI 5.1.x - TWRP flashed - Now how to upgrade to EMUI 8..x ?

[FransisFor]

Dear,

i've successfully managed to unlock my P10 Lite using DC unlocker starting from EMUI 5.1.x

After that i've flashed TWRP (this maybe was an error?)

After that i'm trying to upgrade to EMUI 8.x that is the minimum requirement to go for a CUSTOM ROM.

The problem is: if i'm trying to do that using the official tool in the phone, the update is downloaded but after that TWRP is displayed (sdcard filename looks like encrypted)

How i can proceed to upgrade? the version i'm trying to upgrade to is WAS-LX1A 8.0.0.362(C55)

Thanks!