Good day, mdmchongsme.
QuickBooks Online International version does not have payroll function inbuilt, which includes Singapore. However, we can use third-party software that we can integrate so you can process payroll.
Please check this link to see the supported third-party companies: Third-party payroll integration. In addition, we can record payroll transactions manually using journal entries.
Let me know if you need more help. Stay safe!