Sign in with Slack setupSign in with Slack helps users log into your service using their Slack profile. The Sign in with Slack flow will redirect users to the right Slack URL. Slack will send users back to your service along with the information your service needs. The flow is based on the OpenID Connect standard, built on top of OAuth 2.0. The modern Sign in with Slack works with any package that successfully implements
PHPでSignin with Slackを試す - Qiita
