adb – how to boot successfully in bootloader / fastboot mode on an alcatel 5049z smartphone

I have problems (I am a "novice" with regard to unlocking the bootloader a30 android with a PC …) when booting bootloader / fastboot mode on my stock rom – android 7 – Alcatel a30 (not rooted 5049z?)) smartphone; I tried the power / volume button sequence method … no luck, and I tried the adb method with: reboot bootloader / fastboot adb..always no luck !!!

I would like to know if forum members know how to unlock my a30 bootloader without (if possible?) Reboot to the aforementioned bootloader modes or if this phone charger is unlockable without removing FRP (Reset Protection). factory) ????

Thank you in advance for any useful answer!