Recovering deleted text messages

I may need step by step instructions to help me do that I don’t want to mess up those text are very important they have very valuable info and codes to deposit box my grandparents and parents left me to inherit it there’s 25 passwords and codes for banks all over the world and without them I can’t access them that’s what my grandpa left in writing no code no access he has always told me I’m a bit careless with some things he told me to write down and leave it in a bible I didn’t I saved it on my notes app and text it to myself so I really need help guys please

They’re gone. If you’ve used iCloud Messages, they’re gone. If you have no backups, they’re gone. If you have not used iCloud messages and have a backup from prior to the deletion and are willing to revert your iPhone and its entire contents to that backup, then try restoring and reverting.

The only way to recover deleted messages would be to restore your iPhone with a saved backup. This process is time-consuming so you might want to consider if it is worth it for a couple of messages, and it would be dependant on you having a backup that has these text messages saved, so if you don't back up your phone regularly (I personally have mine done automatically which you can learn about here) then this process might not work.

You may also find this link helpful in regards to restoring your device from a backup.

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

Are you willing to discard all changes made and all messages arrived—everything everything all of your iPhone contents everything everything—back as far as some time prior to when the messages you want to recover were deleted? (Yes, or No.)

Do you still have a backup of your iPhone from before the messages were deleted? (Yes, or No.)

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

Was iCloud Messages previously disabled? (Yes, or No. Disabling that setting now will have no effect here.)

Use Messages in iCloud - Apple Support

If you cannot answer “Yes” to all three of those questions, the messages are gone.

How do I do that