CRITICAL ERROR: The diamond executable can not be found. Please check the install

Hi all,

I am trying to run humann3 which I installed via:

pip install humann --no-binary :all:

but then run into this error when I run the demo:

(biobakery3) samd@Sams-MacBook-Air-7 humann % humann --input demo.fastq --output out

Output files will be written to: /Users/samd/gutmicrobiome/humann/out

CRITICAL ERROR: The diamond executable can not be found. Please check the install.

I have tried installing diamond from source but that does not fix the issue. diamond -V or diamond --version returns nothing either.

I also tried humann2 and get a similar metaphlan error see here CRITICAL ERROR: The metaphlan2.py executable not found

Would love any help on this as I have been stuck for about a week with no avail!
Cheers,
Sam