Home automation not working

Sir how can i get 5v from the any of the GPIO pin because i want to make a home automation from bolt iot using 5v relay and AC bulb in which i can control it with google assistant voice control.
i want to make the project like the below link: https://www.hackster.io/yeshwantnaik/home-automation-using-bolt-962b47
As i tried to control ‘0’ pin by the command https://cloud.boltiot.com/remote/xxxxApiKeyx/digitalWrite?pin=0&state=HIGH&deviceName=BOLTXXXXXX for turning on the relay and https://cloud.boltiot.com/remote/xxxxApiKeyx/digitalWrite?pin=0&state=LOW&deviceName=BOLTXXXXXX for turning off the relay using IFTTT and Webhooks to connect bolt iot with my google assistant account but the problem iam facing is that i am not getting enough voltage(5v) to drive relay…
When i am connecting the relay 5v/Vcc port to the bolt iot 5v then it is working fine but then iam unable to control it by google assistant…
Sir please guide me

Of course you will not get the controlling feature when you connect your relay to 5v pin as this pin cannot be controlled by programming like gpio pins. It simply gives 5v as output.

Coming on to relay part you can use transistor as a switch to trigger your relay using smaller voltages like 3.3v , use a transistor generally a npn transistor like bc546 and a dedicated power supply like a battery to trigger the relay. What we have to do is to trigger the relay by using a dedicated power supply rather than using the power from bolt module .
A transistor has three pins
i) Emitter
ii) Collector
iii) Base
connect the positive terminal of battery with one of the input pins of relay, then connect the other pin of relay with collector of transistor, then connect both the emitter and the negative terminal of the battery to the ground of bolt module.
Now you left with the base of the transistor which you can connect to any of the digital pin of the bolt module in series with a 10k resistor. Whenever base of the transistor goes high the circuit gets completed and the relay gets triggered.

But this circuit is not a good circuit to trigger a relay, as relay has a coil inside it which can store energy and this stored energy can burn your transistor and may be the bolt module because of fly back effect. So to deal with this you have connect a diode (a In1470 diode will work) in parallel to the relay input pins.

**After all this your circuit should look like this ** ---------> https://electronics.stackexchange.com/questions/145504/triggering-a-12-v-relay-with-an-arduino