Make external (guest) users be able to use "Only people in your organization" links

[Tomas790]

I have an integration towards a Sharepoint site. This site is on the testforetaget.com domain. The integration works so that it fetches a "Only people in your organization" link of a given file in the document library of the Sharepoint site. This works fine for people with an azure account for testforetaget.com. 

But we also have people who are guest users. Their accounts belong to another domain than testforetaget.com. They are not able to use these links. They get a message saying "This link is only available to internal users. This link is not available to you."

I guess it makes sense that these users cannot access these links since they are probably not considered to be "a part of the organization". 

I also understand that there are other links which can be provided such as "anyone" and "people with existing access" links. But these are not considered as possible options due to different reasons.

Is there any way to setup the Sharepoint site, groups, azure ad role or something else so I can get "Only people in your organization" links to work for guest users?

[#2]

Have obviously no idea how this is configured, but if applicable consider using sensitivity labels for containers (groups, teams and sites) where you can predefine the default sharing link and/or setup the external sharing settings for the site, for example.

https://learn.microsoft.com/en-us/microsoft-365/compliance/sensitivity-labels-teams-groups-sites?vie...

[#3]

I just came across this post after verifying with support that sharing with 'people with existing access' does not include guests of the tenant, even if they already have access to the site. This makes no sense to me as it forces me as an admin to have to either route all external sharing duties (even sharing with people who already have access) through a site owner, or allow internal users to share the site without the owner's knowledge.
Hopefully Microsoft will change this at some point.