If lost my recovery key but I know my Apple ID and password. What should I do.

The information below is based on Apple's support article: How to generate a recovery key - Apple Support with quoted excerpts. Each section below outlines the different situations and the strategies that may require use of a recovery key. See this support article for the meaning of trusted devices and numbers —> Two-factor authentication for Apple ID - Apple Support

- If you still have access to your Apple ID and password but have lost your recovery key:

"You can generate a new recovery key from Settings or System Preferences on a trusted device." Refer to the steps in How to generate a recovery key - Apple Support about how to do this on different types of equipment (Apple equipment only).

If you have already generated a recovery key and you have lost the key, your recovery contact can help you to get the recovery key.