MusicDigi receives monthly sales reports from all stores and these reports are delivered by the stores on an (approximately) 3 months delay from the end of the month your sales took place in.
For example if you released a single in January, and it started being downloaded and streamed in that month, you can expect your first report to show in your MusicDigi account at the end of April, Reports for the February sales period will be processed in May, and so on...
Your sales reports are available in the Sales section of your artist account under "Reports". Your current balance of earnings will always be visible in the Sales > "Balance" section of the interface.
For more information on how to withdraw your earnings, please visit this article.