In addition to the standard and free add-ons, choosing one of the paid Debutify plans gives you access to premium add-ons. In Debutify 5.0, you can use the Remove Debutify Branding add-on to Remove "Powered by Debutify" at the bottom of all your store pages.
How to Remove "Powered by Debutify"
In Shopify admin, under Online Store, click on Themes.
Select your Debutify Shopify theme and click on Customize.
Click on the Theme Settings icon.
Click on Debutify Premium Add-Ons.
Tick Remove Debutify Branding.
Click Save to apply the changes.