payment.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<payment xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Payment:etc/payment.xsd">
    <groups>
        <group id="offline">
            <label>Offline Payment Methods</label>
        </group>
    </groups>
    <methods>
        <method name="banktransfer">
            <allow_multiple_address>1</allow_multiple_address>
        </method>
        <method name="cashondelivery">
            <allow_multiple_address>1</allow_multiple_address>
        </method>
        <method name="checkmo">
            <allow_multiple_address>1</allow_multiple_address>
        </method>
        <method name="purchaseorder">
            <allow_multiple_address>1</allow_multiple_address>
        </method>
        <method name="free">
            <allow_multiple_address>1</allow_multiple_address>
        </method>
    </methods>
</payment>