MBP2018 dead after bootcamp

https://youtu.be/3IhW722IMwE I was following this guide to install windows on external drive. 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. then clicked on restart windows and while it was restarting (windows restarting screen) i accidentally pressed the power button and mac got shutdown immediately. now nothing happens when i press the power button. it doesn't even power up. tried

1. pressing power button for 30s
2. https://support.apple.com/en-gb/HT201295