3 months minimum age with Singapore airlines.

Cannot travel in the main passenger cabins with you and cannot be classed as a support or emotional support animal under Singapore airlines rules.

It can go as your checked luggage so same flight and safer then cargo, it’s temperature and pressure secured like passenger cabin and all animals crates are securely setup in a seperate area then luggage.

If you can get a direct flight then I wouldn’t worry to much, however stop overs could be the more stressful part for the animal.