Can tap water water water the flowers? Can you water the flowers with tap water?

Some people say that tap water can be used to water flowers, and others say that tap water is harmful to flowers and trees, because it contains chlorine, so it should be watered for a day or two. But for many years, no matter whether it is family flower cultivation or professional flower nursery, whether it is ground planting or potted plants, most flowers and trees are watered with tap water. So far, there is no correct data to prove whether watering flowers with tap water is harmful to the growth of flowers and trees, or how harmful it is.