Looking for logging into the Sign In With Slack site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Sign In With Slack site. After that you can login as usual with your login credentials.
https://api.slack.com/docs/sign-in-with-slack
https://qiita.com/suzutan/items/4070613f356ce0311ce3
https://medium.com/slack-developer-blog/introducing-sign-in-with-slack-290949e1c3f5
https://github.com/pepabo/collec/issues/13
https://get.slack.help/hc/ja/articles/212681477-Slack-%E3%81%AB%E3%82%B5%E3%82%A4%E3%83%B3%E3%82%A4%E3%83%B3%E3%81%99%E3%82%8B
https://get.slack.help/hc/ja/articles/204078066-G-Suite-%E3%82%B7%E3%83%B3%E3%82%B0%E3%83%AB%E3%82%B5%E3%82%A4%E3%83%B3%E3%82%AA%E3%83%B3
https://japan.cnet.com/article/35082359/
https://www.itmedia.co.jp/news/articles/1605/11/news084.html
https://azriton.github.io/2017/06/01/Slack%E3%81%AE%E3%83%9C%E3%83%83%E3%83%88%E3%81%ABOAuth%E3%81%A7%E6%A8%A9%E9%99%90%E3%82%92%E8%BF%BD%E5%8A%A0%E3%81%99%E3%82%8B/
http://miniorange.com/single-sign-on-(sso)-into-wordpress-with-slack-account
https://stackoverflow.com/questions/50971247/expected-behaviour-of-sign-in-with-slack
https://www.cloudsign.jp/features/slack
https://www.onsip.com/blog/third-party-sign-in-log-in-to-onsip-with-google-or-slack