diff --git a/scripts/patchUrls.js b/scripts/patchUrls.js
index 1be9be0c..b8524387 100644
--- a/scripts/patchUrls.js
+++ b/scripts/patchUrls.js
@@ -81,6 +81,36 @@ const getFiles = (directory) =>  {
 }; // getFiles
 
 
+/**
+ * The function filters environment variables and returns only the important ones.
+ *
+ * @returns {object}
+ */
+const filterEnvVars = () => {
+    const vars = process.env;
+    const valid_keys = [
+        "BASE_URL",
+        "MAIN_CDN",
+        "DOWNLOADS_CDN",
+        "API_ENDPOINT",
+        "USER_API_ENDPOINT",
+        "APPINSIGHTS_INSTRUMENTATIONKEY"
+    ]
+    const filteredVars = {}
+
+    Object.keys(vars).forEach(key => {
+        // Check if it can be one of the vars to use.
+        valid_keys.forEach(valid_key => {
+            if(vars.hasOwnProperty(key) && key.includes(valid_key)) {
+                filteredVars[key] = vars[key]
+            }
+        })
+    })
+
+    return filteredVars
+}
+
+
 /**
  * Replaces placeholders formatted as `%key%` with environment
  * variables defined using the same key.
@@ -94,18 +124,17 @@ const main = async () => {
         files = getFiles(directory),
         Replacements = {
             ...extractEnvVars(),
-            ...process.env
+            ...filterEnvVars()
         };
 
-    console.log("+++ extractEnvVars():", extractEnvVars())
-    console.log("+++ process.env:", process.env)
-    console.log("+++ Number of files =", files.length)
+    console.log("vars:", Replacements)
+    console.log("vars number:", Object.keys(Replacements).length)
 
     let counter = 0;
 
     for ( const file of files ) {
         counter += 1;
-        console.log(counter, " - ", file)
+        console.log(counter, " - processing file:", file)
 
         const tmpFile = `${ file }.tmp`;