The best way to access your HDD add-on or SSD add-on is to create virtual drives.
For LXC antlets, you have an additional option. You can enable your LXC antlet to access the add-on in its entirety.
Here's how it works:
Let’s assume the antlet that you want to use the HDD with is named TEST. Please replace the word TEST in the commands below with the actual name of your antlet! Please note: Currently, this only works when the antlet in question is of type LXC.