Retrieve a text message I accidentally deleted
If you have activated iCloud Messages you cannot retrieve it, the message is gone. If you have messages on another device you can look at the message there. If neither of those apply and the message is in your backup you can restore your iPhone from your backup. You will lose anything added since the time/date of that backup.
Restore this backup to a spare device (iPhone, iPad, iPod, doesn't matter), then use iCloud sync for Messages to merge chats with the current phone. You can use iMazing trial to make sure that these messages are actually in the backup before restoring it.
Can I retrieve a message I accidentally deleted
You can't.
Only if you have them on another iOS device under same Apple ID. In this case, you can sync them through iCloud. Also, do you have an iTunes backup with these messages?
I think I do
How do I retrieve a deleted message
How do I retrieve deleted messages
