Following steps will guide you to approve Purchase Order(PO).
Store > Purchase Order > Purchase Order Approval
Step 1 : Open Smaac ERP
Step 2 : Under Store go to Purchase Order then select Purchase Order Approval as shown in the picture
Step 3 : In the new window, grid have all the PO's which are not approved yet. Click on PO which user want to approve and the selected PO will show in grid below the main grid.
Step 4 : User can add remark if he/she want and also can see the preview by clicking Preview, click on Approve to approve the selected PO.
For tutorial of How to create PO click here and for tutorial of How to create MRN click here.