Hi @Ege235
You will need to contact Airbnb support for this type of issue due to security and privacy issues. This can happen due to someone previously having the phone number that you have and they created the account previously. I certainly do not want to lead you into accessing someone else's account so please contact Airbnb and they can certainly resolve this for you.
https://www.airbnb.com/help
David
Superhost Ambassador ~ Host Club Community Leader ~ Experienced Co-Host