Due to Airbnb's channel manager structure, you are only able to link your Airbnb account to one property management app at a time.
Note: Host Tools can connect to Airbnb while another Property Management System (PMS) is still connected to your account by enabling Setup Mode. This allows you to complete onboarding without disconnecting your existing property management software right away. When you’re ready to enable your property in Host Tools, you’ll need to disconnect the other PMS from your Airbnb account and then reconnect Airbnb from Settings > Channels with Setup Mode turned off.
To disconnect your previous software, follow these instructions.
Visit Airbnb.com and go to the profile pic on the top right corner of the page
Go to Account> Privacy and Sharing> Services.
Disconnect any other connected service.
Once this is complete, you can connect Host Tools.