My iMessage doesn't work

iMessage and FaceTime Activation process. Use your Phone number to send Message and Call FaceTime

I request you to go through the steps 4.1, 4.2, 4.3 & 4.4 again (the order is very important).

1. If you get an error when trying to activate iMessage or FaceTime
   1. To use iMessage or FaceTime, you need to activate them on your iPhone, iPad, or iPod touch. If you see an error message during activation, follow these steps.
2. When activating iMessage or FaceTime, you might see one of these messages:
   1. Waiting for activation
   2. Activation unsuccessful
   3. An error occurred during activation
   4. Could not sign in, please check your network connection
3. Check your device settings
   1. Make sure that you’re connected to a cellular data or Wi-Fi network. If you're using an iPhone, you need SMS messaging to activate your phone number with iMessage and FaceTime. Depending on your carrier, you might be charged for this SMS.
   2. Go to Settings > General > Date & Time and make sure that your time zone is set correctly.
4. Turn off and restart iMessage and FaceTime
   1. Go to Settings > Messages and turn off iMessage.
   2. Go to Settings > FaceTime and turn off FaceTime.
   3. Restart your device.
   4. Turn iMessage and FaceTime back on.
5. Still not activated after a day?
   1. It might take up to 24 hours to activate iMessage and FaceTime. If the issue continues after 24 hours, follow these steps:
   2. Make sure that your device has the latest version of iOS.
   3. If you're using an iPhone, contact your carrier to make sure that you can receive SMS messages.
   4. Contact Apple Support.

Wait for some time for it to get it activated. You must have a SMS enabled cellular Plan to activate iMessage.

Watch the GIF below.

You should see as shown in the pic below

.

Once Activated you can activate FaceTime with the same Phone number

If you get an error when trying to activate iMessage or FaceTime ...

https://support.apple.com/en-us/HT201422

Turn on FaceTime

Open the FaceTime app and sign in with your Apple ID. You can also do this from Settings > FaceTime. 

If you're using an iPhone, FaceTime automatically registers your phone number. To also register your email address on your iPhone, go to Settings > FaceTime > Use your Apple ID for FaceTime, and sign in with your Apple ID.

If you're using an iPad or iPod touch, register your email address by tapping Settings > FaceTime > Use your Apple ID for FaceTime, and sign in with your Apple ID.

Then next step is 5.3

1. 1. If you're using an iPhone, contact your carrier to make sure that you can receive SMS messages.

That's it.

Use FaceTime with your iPhone, iPad, or iPod touch - Apple Support

https://support.apple.com/en-in/HT204380