How can I reset apple watch?

I entered the wrong password, and device blocked..

Try to use this guide
https://www.youtube.com/watch?v=OF50PoYJf8c

Have you spent all six password attempts? As I know you can reset your device in two ways: through the Apple Watch app on the iPhone paired with the clock or by using the side button on the smart watch. More detailed infro you can find here https://osxtips.net/apple-watch-factory-reset/