Go to the OpenIPC website and use their firmware selector. Input your SoC (e.g., T31) and sensor. Download the uImage and rootfs.squashfs files. Also download the u-boot if you are replacing the bootloader (risky).
The stock firmware works—until it doesn’t. Here are the primary motivations for users to jump through the hoops of flashing custom firmware. v380 custom firmware
# Check header
binwalk firmware.bin
Step-by-step (high level, assume TFTP method for common devices): Go to the OpenIPC website and use their firmware selector
Thingino is a fork of OpenIPC but focuses on making the process easier for beginners. It supports many of the same T-series chips but offers pre-built images for several popular AliExpress camera models. v380 custom firmware