They call it a common gesture of courtesy to inform people that your home would offer itself to those fleeing some kind of devastation (oppressive regimes, abuse, earthquakes, etc.). However, most people don’t end up in that kind of humanitarian role. What’s the closest you have come?
My mother used to volunteer to help a family of Kurds set up their life in Germany. Last I heard they started their own business. They still keep in touch.
My son helped organise a donation collection for Ukrainian refugees that arrived in our town.