You are able to export data from Arch from a number of pages. The below will show you where and how you can export a CSV file from the portal.
Steps
Navigate to the portal page that lists the data you would like to extract. This could be the Holdings page, the Account Activity page, or any tab listed on the left hand side of the portal.
Click the three dots in the top right corner of the relevant table
Click Export, or the cloud icon with a downward pointing arrow
This will download a CSV of all data listed in the table