This plant ID has recently changed. In addition to the cultivar name being added, this particular listing would technically be a Rhizomatous, not a Rex, but they share the same care information.
General Begonia Care Tips:
Light: Foliage Begonias prefer bright, indirect sunlight, whereas blooming begonias’ light needs vary.
Water: Begonias prefer moist but not soggy soil so make sure the soil and pot are well draining.
Previously labeled ID16