I want to buy a MacBook in installments. What's the catch? Are there any additional payments or requirements?

No catch. If you use the Apple Card Monthly Installment option, the MacBook Air is split into 12 monthly payments of equal value. No additional fees or charges. There is no 24 month option for Macs.

The only requirement is to already have or apply for an Apple Card.

click here ➜ Apple Card - Monthly Installments - Apple

and here ➜ Products you can buy from Apple with Apple Card Monthly Installments - Apple Support

If you use your own credit card from a third party issuer or bank, then you would need to ask them if there are any catches or fees when using their monthly installment option if available for purchases from the Apple Store.

shakhzod0077 wrote:

Can I open Apple Card without SSN? I am visiting scholar and here for 4 months. But I am able to pay monthly even when I go back to home.

No. You need to be a US citizen or legal resident with a US based address to apply for an Apple Card. A SSN would be be had already in either case.