NEIKO 10038A Left-Hand Drill-Bit Set, High-Speed Steel Drills with Titanium Nitride Coating, Reverse-Twist Drill Bits, SAE Sizes, 13-Piece Set

Weld a nut to it, sometimes you can shatter the extracted with a punch & pull the remnants out. Next time I’d recommend trying a left handed drill bit set first. A lot of the times if you use left handed drill bits it will spin the broken bolt out with the bit. These are the ones I use. https://a.co/d/05S7CEwI