How to back up Azure SQL DB into BAK file?

I am trying to create a Bak file format from Azure SQL DB into Azure Storage (like Blob storage) on a daily basis for an external client.

Previously, I had an external client to log into that Azure SQL DB to perform query, but it appears that it is too slow.

So, our team decided to have an external client have an access to BAK file so they can get the file and restore into their SQL DB.

I realized that Azure SQL DB backs up into Bacpac file format, not Bak format.

I am using Azure Data Factory to move data, and I am not sure ADF can be used to do the task.

Please let me know the best practice to generate Bak file from Azure SQL DB and push that file into Azure Blob storage.

Thanks.