To create admin menu in Magento 2, you need to create a menu.xml file in the
app/code/MageMonkeys/HelloWorld/etc/adminhtml/
directory.
<?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="MageMonkeys_HelloWorld::helloworld" title="Hello World" module="MageMonkeys_HelloWorld" sortOrder="51" resource="MageMonkeys_HelloWorld::helloworld"/>
<add id="MageMonkeys_HelloWorld::post" title="Manage Posts" module="MageMonkeys_HelloWorld" sortOrder="10" action="magemonkeys_helloworld/post" resource="MageMonkeys_HelloWorld::post" parent="MageMonkeys_HelloWorld::helloworld"/>
<add id="MageMonkeys_HelloWorld::hello_configuration" title="Configuration" module="MageMonkeys_HelloWorld" sortOrder="99" parent="MageMonkeys_HelloWorld::helloworld" action="adminhtml/system_config/edit/section/helloworld" resource="MageMonkeys_HelloWorld::helloworld_configuration"/>
</menu>
</config>
Then, flush Magento cache by using below command.
php bin/magento cache:clean
And you will able to see below result.


