Click More in bottom right corner

Go to Parts Inventory tab

Select Part to set Unit Cost

Click 3 dots (⋮) next to Restock in top right corner

Select Edit

Enter Unit Cost of Part in Unit Cost field

Click Update in top right corner

Go to Parts Inventory tab

Select Part to set Unit Cost

Click 3 dots (⋮) next to Restock in top right corner

Select Edit

Enter Unit Cost of Part in Unit Cost field

Click Update in bottom right corner