I DO NOT GET VERIFICATION CODE

Telegram platform does not send one time password (OTP) by SMS and does not call when user tries to login in third party app (like Plus Messenger).
But if Plus user has active session on another device and/or in another app then Telegram usually sends OTP to that session.

So
1. Install official app.
2. Log into your account there.
3. Then log into your account in Plus Messenger.

Please note!
If code does not come even when you log into your account by official app then this is Telegram issue, not Plus one. Maybe it relates to Telegram changes of 02/18/2023, and maybe it does not. You may contact Telegram support to get details: Settings - Ask a question.
If you have another device with Telegram app camera then you can try QR-login feature in Plus Messenger: App menu - Add account - three-dots button - QR login.

Advice
If you are going to log out of your account in Plus Messenger or to uninstall app then make sure you have another active session of your account. If you have no another active session then create it: install another Telegram app (for example official one) on some of your devices and log into your account there.