There are some configuration for issue reminder cloud app. You can reach them from the section 'apps' of Atlassian settings. Those configuration is affected by the required permissions.
The periodic reminders can skip not only just Saturday or Sunday but also the entire weekend by choosing two options.
Groups that can create reminders can be restricted. Only ones that is specified here can create reminders. Similarly, groups that view reminder can also be determined.
Users who are in the one of the groups selected for create reminders can see reminders even if they are not in the view reminders group.
Authorization of Slack
To authorize slack application for issue reminder, first ‘Allow reminders in Slack channels' check box must be selected, then 'Configure Slack Access’ is needed to be clicked.
Then, click 'Allow' button on the opening page to give permission to access the slack workspace after selecting the slack workspace to apply in Issue Reminders.
On the page that opens after giving permission, you will see the text “Everything is ok. Return to Jira“. After clicking on this text, the authorization of the slack application will be completed and the page will direct you to the “Reminders App Configuration” page.
If you want to deauthorize the slack application, it is enough to click the “De-Authorize Slack Integration” button.