App store password not recognized

No, you have to sign in using the App Store App. It should be the same password (not passcode). The exception is if the app was downloaded previously using a different account. Do you have multiple accounts, or did somebody else download the app using their account?

Have you tried restarting your device?

When you move country you should not create a new account, you should change the country setting on the one account. The support article Change your Apple Account country or region - Apple Support describes how to change your country setting on everything using your Apple Account, and the requirements and results of doing this.

Using multiple accounts can lead to great complications as you are now experiencing.

Some apps may not be available in a different country.