That's a cam connector usually used on furniture in a box. I had much experience with them in younger days. Lots of variations, search furniture cam connectors, cam lock connectors, cabinet cam connectors, etc. until you find that exact thing.
One side is a "threaded insert", you will need to know the exact size of the thread and pitch including SAE or metric. A good local hardware store will have a thread size/pitch gauge and may have the insert, the other side is a cam lock connector