How to override magento 2 order/items/renderer/default.phtml?

We can override default.phtml file using below way,
Create sales_order_item_renderers.xml in your module layout folder,
File path will be in your module,
app/code/Rbj/Training/view/frontend/layout/sales_order_item_renderers.xml

<?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="sales.order.items.renderers">
            <block class="Magento\Sales\Block\Order\Item\Renderer\DefaultRenderer"
                   name="sales.order.items.renderer.default.configurable" as="configurable"
                   template="Rbj_Training::order/items/renderer/default.phtml"/>
            <block class="Magento\Sales\Block\Order\Item\Renderer\DefaultRenderer"
                   name="sales.order.items.renderer.default.simple" as="simple"
                   template="Rbj_Training::order/items/renderer/default.phtml"/>
            <block class="Magento\Downloadable\Block\Sales\Order\Item\Renderer\Downloadable"
                   name="sales.order.items.renderer.downloadable" as="downloadable"
                   template="Rbj_Training::order/items/renderer/default.phtml"/>
            <block class="Magento\Bundle\Block\Sales\Order\Items\Renderer"
                   name="sales.order.items.renderers.bundle" as="bundle"
                   template="Rbj_Training::order/items/renderer/bundle/renderer.phtml"/>
            <block class="Magento\GroupedProduct\Block\Order\Item\Renderer\Grouped"
                   name="sales.order.items.renderers.grouped" as="grouped"
                   template="Rbj_Training::order/items/renderer/default.phtml"/>
        </referenceBlock>
    </body>
</page>

Replace Rbj_Training with your actual module name.

Clear Cache and check your file will be overridden.