Windows 11 have some particular security requirements, particularly around the availability of a Trusted Platform Module (TPM) 2.0 module on the chipset of your device.
TMP 2.0 is actually pretty old, dating to 2011, with hardware support becoming available around 2015, meaning many older devices actually have the hardware already available but deactivated. This may even be the case for more recent hardware, as some locations such as Russia or China do not support it.
Asus has now started releasing new firmware for their motherboards which enable support for Windows 11. The new BIOS will automatically enable TPMP on AMD systems or Platform Trust Technology (PTT) on Intel ones.
