You can pull data from existing MongoDB deployments,
files into Atlas using one of the following tools managed by Atlas
within the Atlas user interface.
To locate live migration (pull) in the Atlas UI, in the left-side panel of your organization's page, go to Live Migration to Atlas and select General Live Migration.
Use the Atlas user interface to pull a MongoDB replica set into an Atlas replica set cluster.
Use the Atlas user interface to pull a MongoDB sharded cluster into an Atlas sharded cluster.
Live migrate a standalone MongoDB node