Can employer force expired visa employee to complete contract?

They can still force me to work till December 2023 even if my visa is expired already?

My visa will expire in October 2023 and this will only get renewed if I sign or renew my contract.

Yes, you will have to complete your contract duration.

Visa can be canceled at the expiry of the contract. There is no relation between your visa renewal and contract renewal.

You may provide them with prior notice of non-renewal.

But it is illegal to work if you don't have a valid visa, right?

How can I continue working from October to December if I already have an expired visa?

I will get a fine for it.

Your employer has to renew your visa for 3 months.