Do monthly envelopes roll over?

Hi All!
Setting up my budget in the app and wondering if anything leftover in an envelope rolls over to the next month? For example if I budget $200 for utilities but only pay $150 this month, will next month start with $250? What about the reverse? If I budget $200 but utilities are actually $250 this month will it start out next month with only $150?

When creating your fills you have the option to “add” or “set”. If you “add” the amount will rollover. If you “set” the amount starts over with no rollover.

To add on to Wayne’s answer, choosing “add” may mean that you have less than the budgeted amount the following month, if you ended in the red. In your example, if you budget $200 but spend $250, using “Add” would only bring your envelope up to $150 the following month. “Set” would add all $250 to your (-$50) balance, so you’d start at $200 again.
If you happen to go over, it’s best to transfer money from another envelope to keep from going into the red—that way, not only will the envelopes in your next budget cycle be full, you’ll also keep from inadvertently overspending/overdrafting.