This endpoint does slack login user matching process. <b>You must execute this endpoint FIRST TIME you enter on APP.</b> All fields are required. Later, You <b>must include in all calls Header</b>:<br/> <b>Slack-User-Id</b>: slack_user_id__slack_user_company <br/> <i>(example)</i> AAAAAAA__BBBBBB<br/><br/> OR IF YOU PREFER you can include two params<br/><br/> <b>Slack-Uid</b>: AAAAAAA<br/> <b>Slack-Cid</b>: BBBBBBB<br/><br/> And let the middleware makes all happens.