To add a medication, go into your care plans screen, select the care plan (if you have multiple) then click the "+" button next to the type of intervention you want to add, such as Medication/Supplement, Therapy, Nutrition, Physical Activity.

You may delete it on the mobile by clicking on it and viewing more info and scrolling down and then clicking delete. In the web platform, you can click the "x" button on the far right side of the row that the intervention is on.