This knowledge base article walks you through the basic steps to create a special that gives a free inventory item, such as a lock, with a move-in special.
Open the Specials & Discount Wizard and click on Advanced Mode
Click the box for One Time Charges and then Add Item
Select the desired Inventory item from the list and click Select
Fill in the appropriate option for Amount
You will then need to set the period 1 and 2 logic to the desired setting. I have set Period 1 to FULL. Once this is done you will need to assign General Options for this special.
Once the special has been saved you can assign it to the appropriate unit types.
When using the special during a move-in you will see that the lock has been included with the special but the tenant is not being charged for it.
Keep in mind this area is very dynamic and the options are limitless. You could give 5 boxes free, 50% off Bubble Wrap, etc.