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kotlinlang

Is there any payment gateway for Compose Multi Platform, i checked with razrorpay, stripe I didn't find any.

You could try contacting the payment company of your choice and let them know about your needs, they should provide a kmp sdk. It is easy to make. 
The other alternative you have. Try finding one payment sdk that is open source and create your kmp library. You have 2 options 
1- Wrap each platform sdk.
2- If the Android code is in kotlin. Copy the code and put it in commonMain of your library.

Okay,
Currently Any SDKs available in the market to start immediately.

Usually to select a payment gateway you look into various things. Do you plan a card reader feature or just enter the card information manually. Check also the transaction fees, small business benefits, customer support and all that.
Also consider integrating Google pay/Apple pay, I use my mobile wallet all the time when possible.
I am not aware of one that I could recommend at this point. Also many payment processors are requiring to be a partner so they give you access to their system