generate random aplhanumeric string/GUID in json file

I am very new to json files, I have the below json file in whcih I would like to add a random string(aplhanumeric- 8char. for Ex: F21FBE7C) or guid to my "dstpath" . How can I add that ?

 {
  "files": [
    { "filename":"test.zip",
"srcpath":
    "//path/to/source",
"dstpath":
    "path/to/dest/string"

 }
]
}