Thank you for reply. Currently I belong to some organization(I would like not to write it here) registered in Developer Workspace, so I think that I fulfilled all possible requirements. I’ve got registered SmartApp, I can get Authorization Code, Access Token and using this token (like PAN) to get all information that are described in SmartThings API documentation (devices, locations, rules, execute commands on devices etc.), but I would like also to have information about user for which commands are proceeded. Usually portals like Facebook, Github, Gmail, Imgur, Twitter, linkedin etc that are giving possibility to authorize using OAuth2, are also giving possibility to get information about logged user basing on some URL and Access Token. For example for Google it is:
https://www.googleapis.com/oauth2/v3/userinfo (running it with Access Token as bearer will return information about user)
Is something like that or similar available for OAuth for SmartThings ?