Click on the round grey tick on the RHS of the line item and it will turn green. A green tick signals an approved item; a grey tick signals a pending or unapproved item.
Approving an item will automatically input the approval date and amount into the fields in the Estimate Sale section. It will also change the Estimate Status in the Status field from Pending to Approved.
If all items in an Estimate have been approved, Click on the Status Button and change the Job Status to Approved. This will approve all items simultaneously.
Items also become available for invoicing once approved.