Attach your documents to the email as normal then right click one of them and Upload all Attachments > Onedrive:
This will convert them to a hyperlink within the email body, you can move this anywhere in your email:
By default permissions are set to internal TE only, you will get a warning if you are emailing an external address that they will not be able to open it with the default permissions. To fix that, right click the link then go to File Permissions > Manage Access:
Now, change “The link works for” to “Recipients of this message”, and set an expiry date; otherwise, the link will remain active indefinitely
