Access Requests are for requesting access to a specific resource. Each resource has approvers set within admin settings meaning requestors don't need to know who they need to request approval from. An example of where you might use these is for requesting access to particular systems where each system has an owner.
Open @Approvals within Slack via the side bar or search.
On the home tab select Access
Fill in the details of your request and press submit
The approvers will be sent the request to review in Slack
Once the approvers have completed their review the outcome will be visible to you within @Approvals