if the edit tab doesn't appear what should I do

Hello alden37,

Thanks for posting in the Apple Support Communities. We're happy to look into this with you. We understand that you're experiencing some issues with editing messages on iPhone. To start, have you confirmed you're following the correct process as is outlined here: Unsend and edit messages on iPhone - Apple Support?

Are there any actions you've performed to try and resolve this issue? This could be as simple as quitting the Messages app, restarting your iPhone, or even installing the most recent update. If you haven't tried any of those options, you may want to give them a try in the order listed below to see if it helps. If you have updates available, be sure to back up your iPhone before installing.

1. Close an app on your iPhone or iPod touch - Apple Support
2. Restart your iPhone - Apple Support
3. How to back up your iPhone, iPad, and iPod touch - Apple Support
4. Update your iPhone or iPad - Apple Support

Best regards.