If you are talking about Kolkwitzia amabilis (the plant most commonly called Beauty Bush), it is very easy to propagate from softwood cuttings or seed.

For softwood cuttings, take cuttings in late spring or early summer. Make sure they are nodal cuttings with three or four nodes. Plant in a moist (not wet), well-draining medium. Rooting hormone is totally optional, but might slightly increase success rates.

For seeds, clean and dry them well. Then, soak them in initially hot (about 150 degrees F)(I let the hot water run a minute to get really hot) water for about 24 hours. In other words don't remove them, as the water cools, for a day. Then cold stratify them for 90 days. I use a moist (not wet) papertowel, sprinkled lightly with cinnamon (to avoid mold/mildew growth). I place that in a ziplock bag and place the bag in my vegetable crisper. I grew a bunch of them last year and had very high (near 100%) germination rates.

It sounds like you mean Beauty Berry. They have purple berries. There is lots information online on how to propagate them.