There’s no need to download the evaluation version of Windows 11 LTSC. You can download the full-fledged one from here:
They provide original, untouched ISOs from Microsoft along with ways to verify the authenticity of them
You can then activate the system with MAS from the same website:
Beginning with version 3.0, MAS can also reset the evaluation period if you prefer. It uses official activation systems and doesn’t do anything shady. In fact, it was used by Microsoft’s official support staff when their official procedure failed