Wyze C Wire Help

I got an older HVAC system and was hoping you guys can assist with the install. C wire that goes from wall to HVAC system was not connected to anything. See pics below if that is where its suppose to go. See links for pics


I don’t know where the blue wire you put in the wire-nut with the blue thermostat wire goes, but your C is this wire-nut. Just add the blue thermostat wire to this wire-nut (leave the green and purple wires in there too)