Select the Internet Options item in the Tools menu in the Internet Explorer browser (or via the Control Panels) and then the Content tab and the Certificates section and here we press the Certificates button.

The certificates dialog displays all the registered certificates in the Windows system storage, which are grouped by category. The categories are represented by individual tabs in the overview. Most of the private certificates will be assigned in the Personal category.

If there is a certificate that you wish to use with the eFactoring system among the displayed certificates, then you can send a request to the factoring company and use this external certificate (assuming that it meets the criteria for an external certificate).