Saving any MS file directly into our SharePoint site

1. Click Save & Send, and then click Save to SharePoint.

2.It will ask for login details

Find the SharePoint location to which you want to save, and click Save As.

Refer:  https://us.flow.microsoft.com/en-us/galleries/public/templates/f7a46809e53c42108034e56acf83bb79/save-my-email-attachments-to-a-sharepoint-document-library/