On the Sidebar > Payments is where you can add the credit card you’re willing to use for your MyDev account and all of the platforms you’re planning to use, by pressing the “Add your first card” button.
Also, this is where you get the option to deposit funds that you’re planning to use on the platforms, by pressing the “Deposit” button on the right, upper corner.
On the Sidebar > Payments, you will also be able to check your “Remaining balance”, from the deposit funds that you funded.
“Total Paid” is showing you the amount of money you spent so far across all of your MyDev platforms.
As for “Total invoices”, it is showing you the number of invoices that you received, and you can find them all listed down below, having the chance to search, filter, and export them.