Hey there !
How can I connect my 4 channel relay module to bolt device .
Refer to the project - https://www.hackster.io/vkshah2987/home-automation-using-bolt-iot-2f3b5c
You can connect upto 5 channels with the 5 GPIO pins of Bolt Module.
Warning - Take precautions while working with AC supply, never keep the switch ON, before turning on the module. Do not touch any wires when AC supply is ON. If in doubt, send a clear picture of the circuit before turning it on.