Importing MSSQL database into SQL-Server in HC

I want to migrate a MSSQL database from my current provider to the Azure Service. I have opened a trial account and created a MSSQL Server.

Every attempt to import the database backup filename.bak, that I have obtained from my current provider, ends with an error

STATUSMESSAGE {
  "code": "BadRequest",
  "message": "The ImportExport operation with Request Id '93e28b59-938d-47f4-987e-e0f302a5a37b' failed due to 'Error encountered during the service operation. \r\n\tCould not load package.\r\n\t\tFile contains corrupted data.\r\n\t\t\tFile contains corrupted data.\r\n'.",
  "target": null,
  "details": [],
  "innererror": []
}

Is it possible to import an existing DB into Azure without hiring an expert consultant, or am I wasting my time and should start looking for one?