Click show conditions in the trigger wizard. This will open the options to add, edit and delete the triggers. Here you can give conditions for the slides, objects or variables.
To edit the trigger, select the specific trigger that you need and click on edit option in the triggers panel, else you can simply double click on the specific trigger. You can see a blue underlined text or variables in the triggers panel where it helps you to change the options that will come in a drop-down based on the states, variables or layers, etc.