For the Get the Active Payment Method In WooCommerce REST API

functions.php

add_action( 'rest_api_init', 'custom_api_endpoints' );

function custom_api_endpoints() {

	/**
	 * Handle Get Payment Method request.
	 */
	register_rest_route( 'wc/v2', 'get_payment_methods', array(
		'methods'  => 'POST',
		'callback' => 'custom_get_payment_methods_endpoint_handler',
	) );
}

function custom_get_payment_methods_endpoint_handler(){
	$response = array();
	
	$payment         = new WC_Payment_Gateways();
	$payment_methods = $payment->get_available_payment_gateways();
	
	if ( ! empty( $payment_methods ) ) {
		foreach ( $payment_methods as $key => $values ) {
			$payment_methods_details                         = array();
			$payment_methods_details['payment_method']       = $key;
			$payment_methods_details['payment_method_title'] = $values->title;
			
			$payment_methods_details['description'] = $values->description;
			if ( $key === "stripe" ) {
				$payment_methods_details['test_publishable_key'] = $values->settings['test_publishable_key'];
				$payment_methods_details['test_secret_key']      = $values->settings['test_secret_key'];
				$payment_methods_details['testmode']             = $values->settings['testmode'];
                $payment_methods_details['publishable_key'] = $values->settings['publishable_key'];
				$payment_methods_details['secret_key']      = $values->settings['secret_key'];
			}
			$payment_methods_details_arr [] = $payment_methods_details;
		}
	}

	$response['payment_methods_details'] = $payment_methods_details_arr;
	$response['code']                    = 200;

	return $response;
	
}