If you encounter the message "This email address is already invited to another account" when trying to add a user to your project, it means the email is already associated with another organization. Unfortunately, Qonversion does not support retaining access to multiple organizations simultaneously.
Here are your solutions:
Delete from Other Organization: Remove the user from the other organization and then invite them to your project.
Create Independent User: Have the user create a new email account specifically for your project.
For further assistance, contact Qonversion support.