Hi there,
Thank you for getting in touch with us!
If you would like to integrate a new payment gateway there is one of three things you can do:
1) Do this yourself, warning this is approach is not recommended for those who are not an extensively experienced developer. We do not offer adding payment gateway support. For more information on this, please see: https://www.paidmembershipspro.com/gateway/adding-a-new-gateway/
2) Use our WooCommerce Integration to sell Memberships as WooCommerce Products and use the WooCommerce Checkout to handle payments(only works if your payment gateway is supported by WooCommerce): https://www.paidmembershipspro.com/use-woocommerce-sell-memberships-payment-gateway-choice/
3) Get one of our Partner Developers to give you a cost estimate to develop an integration for you: https://www.paidmembershipspro.com/developers/
Hope this helps!