I can’t sign into my account because it’s asking for a recovery key I didn’t generate

You are sign in here .  .  .  with your Apple ID & Password.

Your Apple ID is the personal account you use with all Apple products and services. It includes the email address and password you use to sign in, as well as the contact, payment, and security details that you use with Apple.

You can’t merge multiple Apple ID accounts.

See the following Apple articles:

Set up an account recovery contact

Set up an account recovery contact - Apple Support

How to use account recovery when you can’t reset your Apple ID password

How to use account recovery when you can’t reset your Apple ID password - Apple Support

Help a friend or family member as their account recovery contact

Help a friend or family member as their account recovery contact - Apple Support (IN)

How to generate a recovery key

How to generate a recovery key 

FYI: Make a screenshot or write down your recovery key and keep it in a safe place.

You can also contact Apple support for help, -> Get Support (apple.com)

You have to show proof of ownership of your product, provide all documentation showing your purchase of the device.

If you do not have additional proof of ownership, contact the reseller. They may be able to provide the original purchase document.

Once Apple receive your proof of ownership, Apple will further review your request and provide an update.