I don't think you understand the matter. Try it yourself. Try to order a digital signing certificate yourself using Chrome, Vivaldi, Edge, or Internet Explorer. You will simply fail when you attempt to get beyond the first page. The first 3 browsers cannot be used according to the warning message at the top of the screen, and using IE fails to generate any certificate request even after changing the trusted site settings as per Sectigo's instructions. You simply cannot purchase a certificate using the doorway page that Lindersoft has provided.