Magento 2.4.x Make PO Number Optional

In Magento when we enable PO number (Purchase order) from the admin panel then it is a required field. To make it optional we have to create a plugin. There are the following steps:

Make a copy of the file that is located here to your theme folder:
vendor/magento/module-offline-payments/view/frontend/web/template/payment/purchaseorder-form.html
Remove the required class and data-validate. New code will look like this

<div class="field field-number required">
    <label for="po_number" class="label">
        <span><!-- ko i18n: 'Purchase Order Number'--><!-- /ko --></span>
    </label>
    <div class="control">
        <input type="text"
               id="po_number"
               name="payment[po_number]"
               data-validate="{required:true}"
               data-bind='
                                attr: {title: $t("Purchase Order Number")},
                                value: purchaseOrderNumber'
               class="input-text"/>
    </div>
</div>

3. Download our module that will create an around plugin and it will bypass server-side validation.