config.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Store:etc/config.xsd">
    <default>
        <payment>
            <free>
                <active>1</active>
                <model>Magento\Payment\Model\Method\Free</model>
                <order_status>pending</order_status>
                <title>No Payment Information Required</title>
                <payment_action>authorize</payment_action>
                <allowspecific>0</allowspecific>
                <sort_order>1</sort_order>
            </free>
            <substitution>
                <active>0</active>
                <model>Magento\Payment\Model\Method\Substitution</model>
                <allowspecific>0</allowspecific>
            </substitution>
        </payment>
    </default>
</config>