I will develop a custom approval workflow using FLOW and Outlook.
Up to 2 approvals. (If first level approver approves, then second level approver must approve)
For example, you may have a list in sharepoint, and whenever someone adds a new item, you want an approver to approve the content before allowing it to be visible in the list.
I can create a flow that will email the approver with the details and present them with 2 options (Approve, Reject). I can also add a second approver, so that if approver 1 approves, it goes to a second approver for approval.