Woocomerce custom payment gateway Not working

Hello, I am using WP events manager, but I have problem with pay the events with WooCommerce payment gateway, I can’t find the WooCommerce payment gateways on the Checkout General setting page.

I am using the aamarPay payment gateway on my WooCommerce and use the currency BDT but the plugin& booking time shows error message “There is no payment gateway available. Please contact the administrator to setup it.”