Magento 2 — Module — Create Backend Menu (Example of etc/adminhtml/menu.xml)

This is an example how to create menu on adminhtml/backend of Magento 2. Once you made this file, don’t forget to clear the cache by running bin/magento cache:clear, or bin/magento cache:flush.

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Backend:etc/menu.xsd">
    <menu>
        <add id="VendorName_ModuleName::parentmenu" title="Parent Menu" module="VendorName_ModuleName" sortOrder="51" resource="VendorName_ModuleName::parentmenu"/>
        
        <add id="VendorName_ModuleName::firstsubmenu" title="Sub Menu 1" module="VendorName_ModuleName" sortOrder="010" action="link_one/post1" resource="VendorName_ModuleName::firstsubmenu" parent="VendorName_ModuleName::parentmenu"/>
        <add id="VendorName_ModuleName::secondsubmenu" title="Sub Menu 2" module="VendorName_ModuleName" sortOrder="11" action="link_two/post2" resource="VendorName_ModuleName::secondsubmenu" parent="VendorName_ModuleName::parentmenu" />
        <add id="VendorName_ModuleName::thirdsubmenu" title="Sub Menu 3" module="VendorName_ModuleName" sortOrder="009" action="link_two/post3" resource="VendorName_ModuleName::thirdsubmenu" parent="VendorName_ModuleName::parentmenu" />
    </menu>
</config>