Please note, use this plugin at your own discretion and test everything first. This is a free plugin with no warrantee or guarantee of correct functioning or implementation.
In your WordPress dashboard, go to Plugins > Add New Plugin, and upload the plugin's Zip file. Once installed, go to Plugins > Installed Plugins and activate the plugin called 'Additonal Fees for WooCommerce Cart and Checkout'
Go to WooCommerce > Custom Fees, and add your additional fees and click 'Save Changes'