The Employment Act sets out minimum statutory benefits and entitlements.
https://themalaysianlawyer.com/guide-to-mal...employment-law/

From 1 January 2023, the Employment Act applies to all employees (“any person who has entered into a contract of service”), with the exception of the sections in relation to overtime payments and termination benefits, which will not apply to employees whose wages exceed RM4,000/month(previously RM,2000/month)

1) If your salary is under RM4k, OT is now claimable if you work more than 45 hours in a week.

Hours of work

An employee shall not be required under his contract of service to work —

-more than 5 consecutive hours without a period of leisure of not less than 30 minutes;
-more than 8 hours in one day;
-in excess of a spread over period of 10 hours in one day;
-more than 45 hours in one week,

More than those as mentioned, you have the right to refuse or claim OT.

Overtime payments

Employees with wages of up to RM4,000/month are entitled to overtime compensation under the Employment Act. Pursuant to the Employment Act, for any overtime work carried out in excess of the normal hours of work, eligible employees shall be paid at a rate not less than 1.5 times his hourly rate of pay irrespective of the basis on which his rate of pay is fixed. Here “normal hours of work” means the number of hours of work as agreed between an employer and an employee in the contract of service to be the usual hours of work per day.