If You want to find modules, which will be as compatible with the version of the online store, and also pay attention to the quality of the code, then we offer to view: remove "important security notification" 3.x, this solution was specifically designed for stores, working on the platform OpenCart, with the support of our company from every store that works on CMS Brocart.
When you download a free extension, we do not give 100% guarantee that it will work in your store, please be careful about the installation instructions!
We created a workaround for those that don't have folders under the root one.
If you still want to not move the folder and use this mod to disable the popup
make sure to have a Webserver that supports .htaccess.
We added an htaccess to deny the web access from all in the /storage/ folder.
(tested with 188.8.131.52)