Find your Supercharger invoices
Open Profile › Charge Invoices. The invoices of your paid Tesla Supercharger sessions show up there after each session.
Tap an invoice to see its details: network, energy, duration, price per kWh, fees (charging, parking, congestion), total excl. tax and total. Tap View PDF invoice to open it, or View charging session to find the matching charge.
The invoice’s amount is also used as that charge’s price: it shows Provided by Tesla in its Cost section. See How a charge’s cost is worked out.