I follow all the steps to send photo from ipad via message and complete all 7 steps up until step 8 when I need to share and the arrow button will not click and send, why?

I follow all the steps on the Apple web site to send 2 photos from ipad via message and complete all 7 steps (see below) up until step 8 when I need to share. The share button will not click and send, why?

Send photos on your iPhone or iPad with Messages

1. Open the Photos app.
2. Tap Select, then tap each photo or video that you want to share.
3. Tap the Share button .
4. Tap Options at the top of the share sheet to choose how you want to send the items.*
5. Tap Done.
6. Tap Messages.
7. Add recipients in the To field, and add a comment if you'd like.
8. Tap the Send button .