Hey. You get a duty free allowance of 1 cigar.
Also without a license you can then only bring in up to 400g worth of cigars to actually pay duty on. If you want to do this option, download the customs@sg app and just complete the self declaration and pay on the app.
If if you have more than 400g to bring with you. I will try and find the list of companies that can get you a license. Will PM you, The customs office gave me the list and you should be able to get it sorted through one of these companies before you arrivr.