Unable to send SMS on iPad Pro (2nd Gen)

You must explicitly enable Text Message Forwarding for your iPad on your iPhone.

On your iPhone:

Settings > Messages > Text Message Forwarding - set to ON - and explicitly enable your iPad from the list of devices.

Also ensure that Messages in iCloud is enabled on both your iPhone and iPad:

Settings > [Your Name / AppleID] > Messages - set to ON

More information:

How to forward SMS/MMS text messages from your iPhone to your iPad, iPod touch or Mac - Apple Support

Fault finding if needed:

If you can't send or receive messages on your iPhone, iPad, or iPod touch - Apple Support

I hope you find this to helpful in resolving the issue.

LotusPilot wrote:

Also ensure that Messages in iCloud is enabled on both your iPhone and iPad:

Settings > [Your Name / AppleID] > Messages - set to ON

This is absolutely not necessary. Indeed should you choose to house messages in iCloud, that should be indicated on all your Apple devices. But not using messages in iCloud at all is perfectly fine.

You’re very welcome. It’s an easy setting to miss - and it sometimes gets reset by an undate.

As for sberman’s comment, enabling Messages in iCloud isn’t absolutely necessary - however, as so many users subsequently complain about losing messages, I always recommend this setting.

LotusPilot wrote:

As for sberman’s comment, enabling Messages in iCloud isn’t absolutely necessary - however, as so many users subsequently complain about losing messages, I always recommend this setting.

On the other hand, for those users who accidentally delete messages and wish to recover them, they can be restored from an iOS backup only if they were not saved using iCloud messages.

sberman wrote:

On the other hand, for those users who accidentally delete messages and wish to recover them, they can be restored from an iOS backup only if they were not saved using iCloud messages.

Sadly, that only works for Messages already on the device to which the backup relates (if the backup exists) - as opposed to messages not synchronised with the target device, which is often the cause of subsequent complaint.

Fortunately, the OP can make their own informed choice. My recommendation permits easy reversal if desired; the alternative, restoring messages never present, is PITA to resolve 🙂