Diting stuck on fastboot after TWRP 3.7.1

[DADER]

Hello dear reader
I wanted to update my 12T Pro's recovery from within the recovery itself , phone was on TWRP 3.7.0 and running hyper os weekly. After I choose flash image option from the recovery , I chose the img file and selected boot and marked flash on both partiotions if not mistaken , then I hit reboot to recovery again. since then and the phone got stuck on fastboot even with trying the commands in the pinned thread by @Igor Eisberg Here . Hopefully someone could aid me to unstuck the phone from fastboot ASAP...
Thank you for your help in advance!

 

[gogocar62]

You did everything wrong.
Try to install ROM using fastboot method.

If in the future you want to update TWRP via recovery, follow the picture.

 

[DADER]

Proves how newb I am , Thanks a lot. so the method Igor posted is obselete now? how should I install TWRP ?
to unstuck I flashed offcial hyper os eu rom and planning to use xiaomi eu bat command to install custom rom again. is that correct ?