They are compatible concepts from different traditions, but not identical.
Karma (from Indian philosophy) describes cause and effect across lifetimes — your actions in past lives shape present circumstances, and present actions shape future lives.
BaZi (from Chinese metaphysics) describes the energetic pattern you're born into based on time — it doesn't explicitly address past lives or moral causation.
However, many practitioners see BaZi as a karmic snapshot — the chart reveals the accumulated energetic tendencies you brought into this life. A chart with abundant Resource stars might reflect past-life cultivation of wisdom. A chart with heavy 7 Killings might reflect unresolved warrior energy.
You don't need to believe in karma for BaZi to be useful. But if you do, BaZi offers a fascinating map of what your karma looks like in this particular lifetime.