I managed to use rclone to sync OneDrive for business using multi factor authentication, but could not get sharepoint to work using WebDAV.
Is MFA supported for sharepoint document sync?
Sorry I don’t have much information for this as webdav is now only available to some old tenants… But I looked around and some on the Internet suggested that you may use an app specific password to do the job. Maybe you can have a look at this article: https://support.office.com/en-us/article/create-an-app-password-for-office-365-3e7c860f-bda4-4441-a618-b53953ee1183 
Hope that helps!