Default membership and file sharing controls for SharePoint Online site are based on the type of site created. SharePoint sites and do not allow use of the Anyone with the link (unauthenticated access by anyone with the link) option by default due to security concerns. If you need this capability steps to request it are given below. 

Membership and file sharing by site type:

Site Type	Invite Internal Members (Site membership, including file access)	Invite External Members (Site membership, including file access)	File Sharing with non site Members (Sharing of individual files or folders, Anyone links))
Team Site	Yes	Yes	Yes Use of Anyone links can be enabled by request
Communication Site	Yes	No (can be requested)	No (can be requested) Use of Anyone links can be enabled by request
Microsoft Teams linked site See the Teams guide for specific details based on channel type)	Yes	Yes	No (can be requested) Use of Anyone links can be enabled by request

If you need to share files or folders with someone outside the University or need to use the Anyone with the link permission to a file or folder, you can request the site be set to allow external sharing. Please also see our best practices when sharing files.

Request the ability to share files with external individuals

• To request the ability to share SharePoint files or folders with external individuals, including the ability to use the permission Anyone with the link, submit a request to our team stating the need to allow external sharing and provide the site name or URL.

Request to add external individuals as members of the site.

• If you need to be able to add an external individual as a full member of your site and not just share specific files or folders with them, you can request the site be updated to allow external members. Submit a request to our team stating the need to allow external membership and provide the site name or URL.