Servo motor just hums rather than writing the angle.

Using Arduino Programming Questions
1 
#include <Servo.h>
Servo servo;

void setup() {
    servo.attach(2);
    servo.write(90);
    
}

void loop() {
     
}

This is the code that I'm trying to use. I'm not exactly sure if my issue is a code error or the servo itself. If you use servos then you can probably tell that I'm just trying to write my servo to 90 degrees so I can use it as a kind of baseline for another project. When I upload the code though, the servo makes a humming sound and when I touch it I can feel it vibrating slightly. No actual turning. If I give the arm that I attached to it a push in the direction that I want it to go, it will usually end up going on it's own the rest of the way.

What can I do to fix this?

Here's the amazon link to the servo's that I have

Thank you, everyone.

2

What happens if you turn off the power, gently turn the servo, and then reapply the signal and power?

Did you remember to connect the ground?

3

Same thing is happening, and yes I connected all the wires.

4

Did you connect the servo power supply ground to the Arduino's ground?
You do have a separate power supply for the servo, don't you?

5

The servo library sets the servo to 90° by default. Where does the servo power come from? Try this:

#include <Servo.h>
Servo servo;

void setup() {
  servo.write(30);    
  servo.attach(2);
    
   
}

  void loop() {
     
}
6

If I give the arm that I attached to it a push in the direction that I want it to go, it will usually end up going on it's own the rest of the way.

This reads like it is a power problem.
Can you get a pen and paper, draw how you have everything wired up, take a picture of that drawing and post the picture here?