Headset does not work on the laptop, what to do?

A buddy of mine formatted my notebook and replaced a new HE hard drive with a better SSD and expanded my RAM memory. He then installed Windows 10. Everything works fine again, except the headphones. When I connect it, the sound runs through the notebook speakers and not through the headset.

Am a layman when it comes to computers, my colleague only told me via WhatsApp "These are missing drivers"

What does that mean? Do I have to download drivers? If so, from where and which ones?

Did the headset work on this notebook before?

Yes, all headsets worked before, now none works anymore. I often connected my iPhone headphones beforehand to listen to audio books in bed at night