Hi @Mirian Nwankwo,
I understand that you have taken a back-up of your Microsoft Authenticator on Android and restored the back-up on an iPhone.
Work or School accounts registered with Microsoft Authenticator are device bound. This means you will need to register your new iPhone with your Entra ID work account before you can receive the number-matching verification push notifications.
You can register new devices at https://aka.ms/security-info - Note, you may need an administrator to reset your MFA methods if you no longer have access to the Microsoft Authenticator app on Android and the sign-in requires MFA.
All other accounts that are not device bound will continue to work from back-up - These will be the 6 digit codes that rotate every 60 seconds.
You can read about my experience of changing phones here: How I almost got locked out of 50+ accounts
Please do not forget to "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.