If you want to any WooCommerce compatible payment gateway with Dokan then you can easily use that. Just you have to call the payment gateway in the seller settings page to insert seller payment details.
We do not provide any custom work service. If you want to customize the plugin then you have to hire a developer. After installing a WooCommerce compatible payment gateway if you want seller to insert their gateway details then you have to add a field here- dokan/templates/settings/payment.php.