This usually depends on the state of your oil. If, for any reason, your oil is thick or appears to be crystalline and solid, then we recommend turning on the preheat mode.  In the opposite case, you can ignore this step.

The general vape pen preheating setting is 15s. You can heat it for 15 seconds first, drop the oil and wait for a few seconds because the heat will gradually increase the temperature of the concentrated liquid.