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External sharing in SharePoint is not as easy as it might seem. There are a ton of different options, and it requires a little patience and will to learn how it completely works. Therefore, the main information you need to know is given in this article:
As SharePoint site admin, you should take a look at expiring access for guests to contents of your site.
In Microsoft SharePoint, „guests“ are users who have been given access to a site or document library, but who do not have a full account within the SharePoint environment. Guests may be external users, such as clients or business partners, or they may be internal users who do not need a full account for the purposes of accessing the site or document library.
To give someone guest access to a SharePoint site or document library, you will need to be an administrator or have permission to invite people to the site. You can do this by going to the site or document library, clicking on the „Settings“ gear icon, and selecting „Site permissions“ or „Shared with“ from the menu. From there, you can add the guest’s email address and specify their permissions (such as read, edit, or contribute). The guest will then receive an email with a link to access the site or document library.
It’s important to note that guests in SharePoint may not have the same permissions or access to all features and content as users with full accounts. This can be controlled through the use of permission levels and access controls within SharePoint.