To create a new alarm, click on the small bell icon on the top right corner of the screen, click on "See all alarms", click on "Add alarm" and fill all the necessary information like: name, date, hour etc.
In case that you would like to add low inventory level alarm, go to Resources-> Inventory, find the item for which you want to set a low inventory alarm and press the "Options"->"Set alarm".
Video how to set up low stock alarm HERE.