How custom payment module integrate with Stripe API?

I am working with the custom payment module which is going to complete the payment with Stripe Payment Gateway.(API)
Can anyone please guide me proper steps to place order with this and complete the payment with Stripe Payment Gateway.??
I have created the admin setting where API key and Published Key are set.I am unable to place the order through this gateway and complete the payment.

I have already implemented the Stripe integration, and it is used by dozens of Magento 2 stores around the world.
What is the difference between your custom module and a standard Magento 2 payment module?

This is paid extension??

I have created module for accepting the credit card payment through Stripe Gateway API Integration