Step 1: Install Base Plugin

Install https://www.huntbee.com/base-plugin . If you have already installed this, you can skip this step.

Step 2: Install Guest Wishlist Extension

1. Download the correct package as per your opencart version. The downloaded zip package must have the name guest-wishlist-x.x.x.ocmod.zip
2. Login to your admin panel
3. Go to Extension > Extension Installer. Upload this package (
   guest-wishlist-x.x.x.ocmod.zip )
4. Go to Extension > Productivity Apps. (If you do not see Productivity Apps, it means you have not properly installed base plugin as mentioned in Step 1)
5. You will see Guest Wishlist in the list
6. Click on the Install button
7. Go to Extensions > Modifications. Click on Refresh button.
8. Test the extension.