Cats have an extremely sensitive larynx and if it goes into laryngeal spasm, the airway can be shut off completely, asphyxiating the cat. There is no time to be waiting for a vet's assistance. However, call the vet both for advice and to warn them that you will be coming in if possible. Leave only the head exposed. This will support the cat and control its front limbs. Angle the cat's head back slightly to be able to open up her mouth and see better inside. Use one finger to depress the lower jaw. Use tweezers to remove an object that is obvious. If you can't see what is causing the blockage or it's too deeply lodged or wedged in, do not attempt to remove it.  Do not stick your fingers into the cat's mouth. Not only could you be bitten but you might cause the choking object to be pushed in further. Having a helper to hold down the cat can be a huge help for you. Use the palm of your hand to thump the cat gently but firmly between the shoulder blades. Alternatively, you can apply several quick, squeezing compressions on both sides of its ribcage. To administer squeezing compressions, do the following:  Sit down on the floor with the cat in front of you but facing away from you. Lift the cat's hind legs and hold them between your knees. Place one hand on either side of the cat's chest and squeeze with sufficient firmness to compress the chest by a third.Do not apply excessive force - it may break her ribs. When squeezing, use jerky movements.  The aim is to try to get the cat to cough. Squeeze four to five times; this should be enough to get her to cough out the obstruction. Your cat may faint or become unconscious in response to the lack of oxygen. If so, do the following:  Open up its jaws as wide as possible. There won't be any damage from opening the jaws up wide. Look for an obstruction. If it is easy to see and not wedged in, use tweezers to remove it. In this case, you could use your fingers but only if you're able to avoid putting pressure on the object, as it could wedge it further into the airway....

TL;DR in Indonesian:
Segera atasi situasi tersebut. Selimuti kucing dengan aman menggunakan bahan yang tebal, seperti handuk. Periksa mulut kucing. Coba keluarkan penghalangnya. Perlakukan kucing yang tidak sadar dengan berbeda. Jika Anda berhasil mengangkat benda yang membuat kucing tersedak, segera buat janji dengan dokter hewan. Jika Anda tidak berhasil mengangkat penghalangnya, segera bawa kucing ke dokter hewan.