We will cover two methods: Serial (UART) upgrade (most reliable) and OTA upgrade (if supported).
In sleep mode, use a multimeter to verify current draw matches the release notes spec. wltfqq-124gn firmware upgrade
Look for something like: WLTFQQ-124GN_FW_v2.1.0.bin and a corresponding .md5 checksum file. We will cover two methods: Serial (UART) upgrade