I would like to move the afterMethods xml item which contains the Discount Code and Gift Card code under the billing-step in the module-checkout/view/frontend/web/checkout_index_index.xml, so that it is displayed before the Place Order Button on checkout page.
Basically I want to have the Place order Button as the last component on the page.
I have modified the above answer to make it more easy to learn.
app/design/frontend/Vendor/themename/Magento_Checkout/layout/checkout_index_index.xml
Use the below code
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<referenceBlock name="checkout.root">
<arguments>
<argument name="jsLayout" xsi:type="array">
<item name="components" xsi:type="array">
<item name="checkout" xsi:type="array">
<item name="children" xsi:type="array">
<item name="steps" xsi:type="array">
<item name="children" xsi:type="array">
<item name="billing-step" xsi:type="array">
<item name="children" xsi:type="array">
<item name="payment" xsi:type="array">
<item name="children" xsi:type="array">
<item name="afterMethods" xsi:type="array">
<item name="config" xsi:type="array">
<item name="componentDisabled" xsi:type="boolean">true</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</argument>
</arguments>
</referenceBlock>
</body>
</page>
and for the second file
app/design/frontend/Vendor/themename/Magento_SalesRule/layout/checkout_index_index.xml
use the below code
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<referenceBlock name="checkout.root">
<arguments>
<argument name="jsLayout" xsi:type="array">
<item name="components" xsi:type="array">
<item name="checkout" xsi:type="array">
<item name="children" xsi:type="array">
<item name="steps" xsi:type="array">
<item name="children" xsi:type="array">
<item name="billing-step" xsi:type="array">
<item name="component" xsi:type="string">uiComponent</item>
<item name="children" xsi:type="array">
<item name="discount" xsi:type="array">
<item name="component" xsi:type="string">Magento_SalesRule/js/view/payment/discount</item>
<item name="sortOrder" xsi:type="string">0</item>
<item name="children" xsi:type="array">
<item name="errors" xsi:type="array">
<item name="sortOrder" xsi:type="string">0</item>
<item name="component" xsi:type="string">Magento_SalesRule/js/view/payment/discount-messages</item>
<item name="displayArea" xsi:type="string">messages</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</argument>
</arguments>
</referenceBlock>
</body>
</page>
First of all I needed to disable the afterMethods component from billing step.
To do so I added this code in app/design/frontend/Vendor/themename/Magento_Checkout/layout/checkout_index_index.xml under checkout > children node.
<item name="steps" xsi:type="array">
<item name="children" xsi:type="array">
<item name="billing-step" xsi:type="array">
<item name="children" xsi:type="array">
<item name="payment" xsi:type="array">
<item name="children" xsi:type="array">
<item name="afterMethods" xsi:type="array">
<item name="config" xsi:type="array">
<item name="componentDisabled" xsi:type="boolean">true</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
Then in the app/design/frontend/Vendor/themename/Magento_SalesRule/layout/checkout_index_index.xml file update the code to set the discount node as child of before-place-order node.
<item name="billing-step" xsi:type="array">
<item name="component" xsi:type="string">uiComponent</item>
<item name="children" xsi:type="array">
<item name="payment" xsi:type="array">
<item name="children" xsi:type="array">
<item name="payments-list" xsi:type="array">
<item name="children" xsi:type="array">
<item name="before-place-order" xsi:type="array">
<item name="children" xsi:type="array">
<item name="discount" xsi:type="array">
<item name="component" xsi:type="string">Magento_SalesRule/js/view/payment/discount</item>
<item name="sortOrder" xsi:type="string">0</item>
<item name="children" xsi:type="array">
<item name="errors" xsi:type="array">
<item name="sortOrder" xsi:type="string">0</item>
<item name="component" xsi:type="string">Magento_SalesRule/js/view/payment/discount-messages</item>
<item name="displayArea" xsi:type="string">messages</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
Same thing can be done for gift card.
