https://articlescad.com/using-....a-cat-flap-in-bifold
If you want to allow your pet to come and go whenever they want without opening the door, you can put in an animal flap. However, you should always hire a vetted professional to do so. They can take care of fitting different kinds of cat flaps to various walls and doors. Installation With a cat flap your pet can enter and leave the house at will, without needing to open the door. The range of pet flaps available on the market is vast, including microchip-proof and bite-proof doors to fully enclosed cat flaps. They com