Manual Backup Cosmos DB

Hi,
Tried to export data in CosmosDB but it was not successful. According to https://docs.microsoft.com/en-us/azure/cosmos-db/storage-explorer, by using this tool I can export the data inside the cosmosdb, but no option to export. Tried to do the instructions here https://azure.microsoft.com/en-us/updates/documentdb-data-migration-tool/ and https://docs.microsoft.com/en-us/azure/cosmos-db/import-data#JSON, but error is being encountered.

Can you help me how to do this in Data Factory or any steps just to manual backup cosmos DB?

Thank you.