How to use Cloud Models for Revit to collaborate with others in the cloud.
Team members can work on the cloud with the Revit team only or with external stakeholders (by publishing the model).
Follow these steps to work on a non-workshared model with the internal team using Cloud Models for Revit
Start Revit and make sure you’re signed in to your Autodesk account.

(Save As) 
(Cloud Model) (see also the
Video: Save a Model to the Cloud).
When you use the Open tool in Revit to access cloud models, Revit ensures that you are working on the latest version of the cloud model. You can also open or restore an earlier version of the cloud model, if necessary.
When you open a model, you must use the same version of Revit in which the model was created. A model created in Revit 2026 will not open in Revit 2027 and vice versa. If you want to open a model in a newer version of Revit, you can either upgrade a cloud model or download it, open in the newer Revit version, and then save back to the cloud as a new model.