How to set script root for Bitbucket Server ScriptRunner on Windows?

[Mohamed]

I have a Bitbucket Server 5.8.1 instance with ScriptRunner 5.4.29. I'm trying to install a web fragment defined in a .js file. I put the file in BITBUCKET_HOME\scripts, but I get this error message when I try to add the script fragment:

Could not find <tt>pull-request-banner.js</tt> in configured resource directories: 

Also here is a snapshot of the error.

After a lot of reading, I think my ScriptRunner installation does not have a script root defined although I found a `scripts` directory exist in `BITBUCKET_HOME`. Also, It looks like I need to set this environment variable as follows (per this article):

set JAVA_OPTS=%JAVA_OPTS% -Dplugin.script.roots=/usr/opt/scripts

I do not know how to set the scirpt root on Windows. Please help.