Watch this Gif or follow the steps below:
Step 1: Click 'Search for records'.
Step 2: Choose from the dropdown list one of the supported record types you want to search for and enter in the search criteria (company, name, invoice number etc.) and hit enter.
Choose the record you want to search for (1)
Type in the search criteria and hit enter (2)
Decide if you want to include attachments (3)
Check off the record(s) to attach it to (4)
Hit 'Attach' (5)