When you type the target name in the What would you like to predict? field, if the target has only two values, DataRobot will assume you are building a classifier. It will order the values and the highest value will be considered the positive class.
If you are unsure which value is the positive class you can view the Advanced options. Then, view Additional and scroll down to see the positive class assignment option; you could also change the positive class here if you want.
Hope you find this quick tip helpful!