QT6 is on 5.15.5 kernel, Honister Yocto, Qt 6 is built into the Linux image in the Yocto Project environment with the command bitbake imx-image-full. For more details on Qt enablement, check out
the README in the meta-imx repo and the i.MX Yocto Project User's Guide.
Even I tested it as L5.15.52-2.1.0, it didn't work.
I installed L5.15.32_2.0.0