MacBook Pro not powering up after installing windows on external drive

I was following this guide to install windows on external drive:

How to install Windows 10 "Boot Camp" on a Mac External Drive the EASY way! (2020 edition) - YouTube

I was able to boot into Windows the first time. I was at step 17:06 installing BootCamp drivers but the setup got stuck at "usb virtual host controller". Waited for about 20mins. then killed the process from task manager, I then clicked on restart Windows and while it was restarting (windows restarting screen)

I accidentally pressed the power button and system shutdown immediately. now nothing happens when I press the power button, no backlit, no fan, nothing . it doesn't even power up. I tried the following:

1. Pressing power button for 30 secs

2. How to reset the SMC of your Mac

3. Reset NVRAM or PRAM on your Mac

Any idea what could be the possible reason?