Go to the Property Profile, and click Key set.
Then click add new key set
Then enter in the Key Set name (this will default to first line of address), the Key Set code, number of keys in the set, branch it belongs too, and any other added access info you want to include.
You then have the option to upload up to 7 photos with this key set. This could be a photo of the key set itself so you know what it looks like when you check it out of the office.
To do this, click the grey box with the +
Once you have filled in all information, and added a photo if you wanted too, click 'Add'