Windows driver without test mode

For Windows operating systems the driver has to be signed via "Attestation Signing". This requires an EV certificate.
Microsoft provides relevant instructions: https://docs.microsoft.com/en-us/windows-hardware/drivers/dashboard/attestation-signing-a-kernel-driver-for-public-release
The drivers created in this way are also suitable for devices that have secure boot enabled.

Microsoft announced that the previous procedure using CrossSigning certificates (signing tool with parameter /ac) will be discontinued from July 2021. After this date it can no longer be used (depending on the expiry date of the individual CrossSigning certificate), as documented here.
Versioned C++ projects, which are loaded via the TwinCAT Loader, have been available for TwinCAT C++ for some time; they are not drivers for the purposes of the operating system. Beckhoff therefore recommends using versioned C++ projects.

A guide is available in the How-to section for the migration of TwinCAT C++ drivers to versioned C++ projects.