If the property is not yet registered with Orento, then you need to send a Co-Hosting request to be approved by the property owner / host. This request consists of information on property listing and your proposed co-hosting fee.
If the property is already registered with Orento, the host can send you a Co-Hosting invitation to help manage their rental property.
Make sure your account is verified, you can see this information under your account and trust & verification, or start verifying here. Only when the account verification process is successful, the host will receive your co-hosting request. If so, please remind the property owner again to approve your co-hosting request.
You can still advertise and manage the property, however not as a Co-host but as a Host. Unfortunately you cannot enjoy all the features that are only available for Co-hosts.