AOSP: Can't Run Emulator

I'm a AOSP newbie. I am following this tutorial.

I have successfully synced my repo to tag android-11.0.0_r29.

I set lunch to aosp_arm-eng. The build reports:

Code (Text):

1. ...
2. [ 99% 90444/90520] //art/build/apex:art-check-debug-apex-gen generate art-check-debug-apex-gen.dummy
3. --bitness=auto, trying to autodetect. This may be incorrect!
4.   Detected multilib
5. [100% 90520/90520] Target vbmeta image: out/target/product/generic_arm64/vbmeta.img
6.  
7. #### build completed successfully (05:25:57 (hh:mm:ss)) ####

However, when I attempt to run the emulator:

Code (Text):

1. clayton@ubuntu-20-aosp:~/aosp$ emulator
2. emulator: ERROR: Can't get kernel version from the kernel image file: '/home/clayton/aosp/prebuilts/qemu-kernel/arm64/ranchu/kernel-qemu'

Have not found a solution. Please help.