Once you log into ResNexus go to the grid. You should be familiar with this page. The reservations grid displays all room reservations 1-3 months at a time.
When you set dates for minimum nights they will show in red above and below the appropriate dates on the reservations grid. You can also see the minimum nights by hovering over a specific date on the grid.
It is up to you to pay attention and be aware of the red above and below the dates when booking a phone reservation. ResNexus won't lock you into booking minimum nights for a phone reservation if you decide to book a guest for one night instead of the minimum nights requirement.
Then book the reservation as usual, filling out Guest information and getting a credit card on file.
For more information on minimum nights, visit How to add Minimum Nights.