I invited an external users to our SP site and when they clicked on the link found in the email invite they get "You need permission to access this site." Obviously, I gave them access otherwise they would not have received the email invite, but yet they still get "You need permission to access this site." Is there a reason why?
There are a huge number of reasons why they get that error message but the most common one seems to be that they are logging in with a wrong account or that the default page of the site is not shared with external users 😒
i think you must create specific group and add this account to it and then send invited link for he/she to Sharepoint site .