M5Stack have GROVE connector for the LED extension. check out here. https://www.aliexpress.com/store/product/M5Stack-Official-Connector-Grove2Grove-Grove2Pin-Grove2SERVO-5pcs-a-set-Three-kinds-Optional-Grove-to-GROVE-PIN/3226069_32960512299.html?spm=2114.12010612.8148356.15.22f0659dLlCy6X