Stem begonias (in this case BEGONIA ANGEL'S WINGS) can be quite easily propagated through the stem cuttings; each stem cutting should have at least two nodes from which the new shoot will come; you may either put the cuttings for 2-3 weeks into water to root or plant them directly into the well drained soil - keep the pot at the warm & humid place (e.g. under the glas so that you get kind of micro-climate as long as you do not have a heated green house). Generally each cutting starts rooting and growing within 3-6months accordingly. Begonias appreciate bright / semi-shady locations (no direct sun).

Wishing you 🍀"GOOD LUCK"🍀 with your propagation!