Greetings Pcz1009,
For help adding tickets back to Wallet on your iPhone, follow the guidance found here:
Add, use, and share boarding passes, tickets, and other passes in Apple Wallet - Apple Support
"How to add a boarding pass, ticket, or other pass to Apple Wallet on your iPhone
- Open the app, email, notification, or other communication that contains your boarding pass, ticket, or other pass.
- Tap Add to Apple Wallet.

- Follow the instructions on the screen.
- If necessary, tap Add in the upper right corner.
If you don't see an option to add your boarding pass, ticket, or other pass to the Wallet app, contact the merchant or company that issued it to make sure they support passes in the Wallet app.
When you add a boarding pass, ticket, or other pass to the Wallet app on your iPhone, you automatically add it to the Wallet app on your paired Apple Watch.
Learn how to remove a pass or ticket from the Wallet app."
Take care.