How do I retrieve text messages

If you go to Settings > [your name] > iCloud, is the switch turned on for Messages?

If it is, you won't be able to retrieve any deleted texts.

If it's turned off, then you would need to have a backup that contains the messages you are trying to recover.

If you have such a backup, then you'd need to restore your phone to that backup.

Note that doing this will lose any data between now and when this backup was made

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support