How can I match orders registered on Everflow with the orders registered in my store?

To check referred orders, add the 'Order number' field to your reports.

(1) Go to Reporting > Conversion report, and select a time frame.

(2) Go to the three-dots button and select 'Columns Customization'.

(3) Make sure that 'Order Number' column is selected -- if not, turn it on and then click 'Apply'.