How connect Subiekt123 to KSeF by a certificate
Open Subiekt123 in your browser
Log in to Subiekt123 with your InsERT account (Konto InsERT).
In the upper right corner of the window, click on the KSeF icon.
Click on the "Konfiguracja"(Configuration) menu, then select the "Połączenie z KSeF" (Connection with KSeF) line and click on the "Połącz" (Connect) button.
Confirm your authority by logging into your InsERT account.
Upload the certificate (*.crt) and the associated private key (*key) file.
Enter the certificate password in the field labeled "Wpisz hasło" and submit the form using the button at the bottom.
If the certificate, key, and password match, you will be able to use the Subiekt123 functions in accordance with your KSeF permissions.