If still stuck, try Apply update from ADB to sideload stock ROM.
before attempting any reset or flash to avoid a "hard brick" during the process. If you can tell me what happened right before the phone bricked How To Unbrick ZTE Blade A34
The ZTE Blade A34 (likely Unisoc/Spreadtrum or MediaTek chip) can be flashed using (for MediaTek) or ResearchDownload (for Unisoc). If still stuck, try Apply update from ADB
Without official firmware + firehose, hard brick is for most users. If still stuck