Hello Buddhabarkenya.
If I'm understanding correctly, you are having trouble changing the Apple ID for your iPhone because you forgot the password and you lost the recovery key as well. I will be happy to help.
Check out the steps below to see if it helps from our article:
Recover your Apple ID with two-factor authentication account recovery
Account recovery is an automated process designed to get you back into your Apple ID account* as quickly as possible and deny access to unauthorized users. For your security, recovery might take several days or longer, depending on the verification information that you can provide.
* Learn how to sign in to your Apple ID or how to reset your Apple ID password.
Use account recovery only as a last resort when you can’t sign in or reset your Apple ID password. Before you start account recovery, confirm that it’s right for you:
- Have you tried to reset your forgotten password from a trusted device? This is the quickest way to reset a password. Don’t start account recovery for a forgotten password unless you can't access a trusted device that has an enabled passcode.
- Will you soon have access to the trusted device that displays the verification code that’s required to sign in? If so, don’t use account recovery. It’s usually faster to wait until you can access a trusted device than to wait for account recovery.
- If you can't access any of your devices, you can also try to reset your Apple ID or password from a friend or family member’s iPhone, iPad, or iPod touch. Open the Find My iPhone app. If a Sign In screen appears, tap Forgot Apple ID or Password, then follow the onscreen steps. Don't see a Sign In screen? Tap Sign Out, then choose Forgot Apple ID or Password.
Did you try the previous instructions and still need help? It’s time to request account recovery. Use Settings on your iOS device or System Preferences on your Mac:
- Go to Settings > Sign in to your [device]. For iOS 10.2 or earlier, go to Settings > iCloud.
- Tap Don’t have an Apple ID or forgot it, then tap Forgot Apple ID.
- Enter your Apple ID, then tap Next.
- Enter your trusted phone number, then tap Next.
- Finish the onscreen steps, which differ based on your access to your trusted phone number or another device.
- Go to Apple menu > System Preferences, then click iCloud.
- Click Forgot Apple ID or password.
- Enter your Apple ID, then click Continue.
- Enter your trusted phone number, then click Continue.
- Finish the onscreen steps, which differ based on your access to your trusted phone number or another device.
Are you still unable to start the account recovery process? Only if you can't access your trusted device or a different iPhone, iPad, iPod, or Mac, go to iforgot.apple.com. Enter your Apple ID, enter the code you see, then click Continue. Enter your trusted phone number, then click Continue. Choose "Don’t have access to your trusted devices or phone numbers." Choose Start Account Recovery.
After you request account recovery, you get an email with a confirmation of your request, the date and time of when you can expect to regain access, and a link to cancel account recovery. Next, wait for the recovery process to finish, which might take a few days or more.
When the process completes, Apple sends you a text or automated phone call with instructions to regain access to your account. Follow the instructions to immediately resume use of your Apple ID.
Cheers.