What is the rules for Cash Settled contract?

Cash settlement on expiration month is not supported.

Opening of new position(s) for Cash Settled contract is not supported 2 business days prior to the Last Trading Date (LTD). You are only allowed to close your position(s) during this period.

Any accounts that continue to hold a cash settlement contract that are close to the expiration day will be subject to forced liquidation. This will occur 1 business day before the Last Trading Date (LTD). The forced liquidation will be conducted on a best-effort basis at 11 AM SGT.