Picture

Turn on MMS messaging, if it’s not enabled.

Settings > Messages > MMS Messages

If that’s on, turn it off, restart your iPhone, and turn it on.

Restart your iPhone - Apple Support

If that doesn’t work, check with your carrier.

“Send pictures”? How? Using Messages? Doing so requires MMS Messaging through your cellular carrier. MMS requires both the following:

• Settings > Messages > MMS Messaging = “on”
• Permission to use MMS from your cellular carrier. This may cost extra.