In the SharePoint Online, you could share files with external users through Anyone link. When external users open files by through Anyone link, they do not need to login in Microsoft account.
Here are steps about how to share files with external users through Anyone link.
1.Enable external sharing in the tenant level. Go to SharePoint admin center -> Polices -> Sharing -> Set Anyone in the Content can be shared with section.
2.Enable external sharing in the tenant site level. Go to SharePoint admin center -> Sites -> Active sites -> Select the site -> Sharing -> Set Anyone in the External sharing.
3.Share a file with external users.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.