My iPhone won't let my send pictures on iMessage?

I'm not sure why this happens an I checked all through my settings and I didn't see anything that could be helpfull. I try and press the picture button but nothing happens. It's a "new" used phone but we restarted it so I don't know what the problem is.

There has been stuff going on with imessage lately with it not being able to send messages, not being able to get on imessage etc.

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