There maybe instances where a record needs to be Approved but may not necessarily need to go through a formal Approval process.
If it is enough for an Administrator to check the record details and approve themselves then they have the ability to do so.
In this instance there is setting in the Approval Configuration area called 'Allow Self approval if User is an Administrator'
If this option is set to 'Yes' in the [...] more actions options of a record, an Administrator will have an additional option [Set Approval status to Approved]
Click this option and the Admin will be prompted to add an Approval note and once [Saved] the record will be updated to Approved.