My apple watch wount charge or force restart
series 6 watch does not want to forse restart
Apple Watch Series 6, watchOS 9
If you tried all the steps in:
If your Apple Watch won't charge or it won't turn on - Apple Support
including If you still need help, contact Apple Support.
then I suggest your best option may be to make an appointment at the Genius Bar in an Apple Store near you and let them look at it:
Genius Bar Reservation and Apple Support Options - Apple