You can install it for ColdFusion as follows:

1.  Download and install CommandBox.
2.  Use CommandBox to install the Proof Key for Code Exchange (PKCE) tool, using the command install pkce

A practical example with:

• ColdFusion 2021 Update 12 on 64-Bit Windows 10 

1.  Download CommandBox., choosing the "Windows JRE-64"version. It is a ZIP file. 
2.  Extract the zip to, for example, C:\temp.
        In this case, the result is the directory C:\temp\commandbox-jre-win64-5.9.1.
3.  Double-click on box.exe , opening the Command Prompt, and wait till you get the CommandBox prompt.
4.  At the prompt, type update --system and press [ENTER]. Wait for CommandBox to completely update.
5.  At the prompt, type install pkce and press [ENTER].  That will install/create the PKCE package.
       In this case, the new directory C:\temp\commandbox-jre-win64-5.9.1\pkce and the new file C:\temp\commandbox-jre-win64-5.9.1\box.json appear. Verify that the new directory contains the component pkce.cfc.
6.  Copy the pkce directory to a location in your ColdFusion application.
7.  (In your ColdFusion application) Create the page pkceTest.cfm within the directory pkce and launch it.
   

   <!--- pkceTest.cfm --->
   <cfscript>
    objPKCE = new PKCE();
    struPKCE = objPKCE.generatePKCE();
    writedump(var="#struPKCE#", label="PKCE object");
   </cfscript>
   ​