Hi:
Your PC won't be able to run W11 for more reasons that that.
As of now, Intel PC's need to have an 8th gen core processor or newer and a TPM having version 2.0.
The HP 6300 Pro only as a TPM version 1.2 and it cannot be upgraded.
If you want to enable secure boot, you would need to reinstall W10 in EFI mode.
To do that, you boot your W10 installation media from one of the EFI boot sources listed in the F9 boot options menu (EFI USB or EFI DVD).
Windows 11 requirements - What's new in Windows | Microsoft Docs
List of supported Intel processors...
Windows Processor Requirements Windows 11 Supported Intel Processors | Microsoft Docs