I cannot use the woocommerce thank you page becuase of the payment gateway.

I use the payment gateway plugin name WPDT-wc-payment to Take payments in person via BACS. More commonly known as direct bank/wire transfer, then that plugin give the customer attach file to let us know that they already paid.

but we cannot use that with woocommerce thank you page.
I attach file that plugin and photo to you

please help.
Yours Sincerely,
Ratchapol Suntisetthasin