This Microsoft Intune blog post will explain joining a Windows device to Entra ID after the operating system installation is completed.
Joining new machines to Entra ID and Intune is possible after the OS installation or later.
Usually, joining the device after the OS installation and before you sign in using a live or local account is recommended.
Joining Windows Device to Intune after OS Installation
Follow these steps to join a device to Entra ID after the OS installation.
When reaching the Who owns this PC step? Screen select the following option:
This device belongs to my organization
Enter your Microsoft 365 username and password.
Once authenticated, you can sign in and register the device with Entra ID.