Apple 6S can't send text messages, but can only receive them.

If the mobile phone can't send short messages, I suggest you check in the following ways:

1. I suggest you change your mobile phone and see if you can send text messages.

2. If you can send a short message, I suggest you re-insert the card into your mobile phone and send yourself a short message to see if you can receive it.

3. If not, I suggest you check whether it is a sim card problem;

4. Check whether the number of SMS center is set correctly.

If you still can't solve your problem, I suggest you take your mobile phone card to the local business hall for testing.