VsCode Keil Studio Pack Post Build Steps

Hello,

I'm having an issue with the Keil Studio Pack (v1.18.3) not recognizing my post build steps.  I've try the following in my csolution and cproject files:

  executes:
    - execute: Generate CRC
      run:  $SolutionDir()$/../tools/CRC/CRCHex.exe $input$
      input:
        - $hex(context)$
        - $SolutionDir()$/../tools/CRC/CRCSettings.XML

However, when I build I get this messages:  "warning csolution: key 'executes' was not recognized."  And my post build steps do not run.  Is there something wrong with the way I setup my post build step?  Does Keil Studio Pack currently support the 'executes' key?  I followed this guide for setting up my post build steps:  github.com/.../YML-Input-Format.md