If I understand, you hooked your ESC up to a servo tester, and the motor operates? If so, that shows your ESC is able to power your servo tester, and hence it should also power your receiver. It would also prove your ESC signal wire is working - which bring into question your receiver’s or transmitter‘s throttle channel.
What I did was I plugged my ESC into the receiver, and plugged the lead of one of the servos that control the flaps into channel 3 (throttle) on the receiver, plugged the battery into the esc and tested that circuit, using the transmitter. When I moved The flaps, they worked flawlessly, which means that the receiver is not broken.