how can I use boot camp with M1 chip

There is no option to use Boot Camp with an M1 chip. See the following from Install Windows 10 on your Mac with Boot Camp Assistant - Apple Support

Boot Camp requires a Mac with an Intel processor.

There is a 3rd party option: https://www.parallels.com/products/desktop/

It is. There may be cheaper options but I.m not familiar with them. Some one else here may be able to help. But that doesn't change the fact that Boot Camp is not an option; there is no way to use it.