fix arrays, use both patches

deployment/integrate/custom/fix-prometheus-namespace.json

@@ -1,3 +1,3 @@
 [
-    { "op": "replace", "path": "/subjects[0]/namespace", "value": "your-prometheus-namespace" }
+    { "op": "replace", "path": "/subjects/0/namespace", "value": "your-prometheus-namespace" }
 ]

deployment/integrate/custom/kustomization.yml

@@ -4,4 +4,5 @@ resources:
   - ../base/
 transformers:
   - use-custom-namespace.yml
+  - fix-podmonitor-namespace.yml
   - fix-prometheus-namespace.yml