How often should multiple POV be used?

Write it the way that works best for your plot.

If you are writing mainly from a single character's point of view and you feel switching to the other POV only a few times during the novel is jarring, you can employ bridges whenever you do, e.g. having your main character think or say something like: I wish I knew (imortant piece of information) just before switching to the other POV when / shortly before that character finds out (important piece of information), or if they started off together, have her wonder what the other person is doing.

There is no need to have both POV for the entire book or to try and write only from one character's point of view if you need to include another POV for a short while. Many authors have written works where they mainly follow one or two characters or groups but include short sections that follow a different character or group. A good example is Tolkien's Lord of the Rings, after the original fellowship is split, not everything experienced by each group gets told from their POV, only those parts that are needed to move the plot along and even after the action is over and they are catching up, only important points where we were kept in suspense during the narrative are cleared up.

For me, while yes there are possible duplicates, they are not exact duplicates questions

But Cheyenne, do read the Q. In the POV tag for the many ways to deal with multiple povs

In your case I would get confused if it is only for 3-4 chapters that I get a second POV, commit to it or don’t, no halfway mesure....

1. Stay with a single character

The information that was to be given by the second character can be in the form of a prelude and the rest found indirectly by the MC.

2. Stay with both characters

Though for that to work they need to have a more even share of the book. Find ways, complications, subplots, to give more room to the male POV.

3. Introduce other characters

If you can’t use the male POV for more than 3-4 chapters, consider adding extra POV to balance the MC. If you interlace the MC with 3-4 other povs, I don’t think it will be confusing, and always coming “home” to the MC, after each other povs, can help anchor the story.