Xiaomi device got blank screen after flash a rom, need help :'(


Jun 15, 2019
I am trying to flash android Q beta into K20 pro today and as a result it got blank now. I bought this device which come with global rom as seller claim and every time it's reboot, there is a word that said, it's unlocked. Today, I found this website, https://www.getdroidtips.com/android-q-beta-redmi-k20-pro/ and so i decide to update it by following the instruction in that website. First, I download the rom from the link that they provide and then i reboot to fastboot mode and try to flash the phone. At first, i got error by saying some kinds like mismatch device and image file. A while later, i saw a video here on youtube
and i try to follow them. I thought it should be okay because my phone is Mi 9T pro (in the setting) and K20 pro is the same so i decide to follow them by delete that two line inside the .bat file and then flashing was success but from here, my device screen got blank nothing is display. I have check on pc and i see it's can be found inside flash tool. I have checked if it is unlocked but it is not and i have tried to unlock it but the xiaomi unlock told tell me that "Current account is not bound to this device" and ask me go to developer option to add my account. But the problem is that, the fone is blank now. How can i do? or what should i do. Please help me :'(