Simple bash is enough

prowlarr/rootfs/etc/cont-init.d/20-folders.sh

@@ -1,4 +1,4 @@
-#!/usr/bin/with-contenv bash
+#!/bin/bash
 
 if [ -d /config/prowlarr ]; then
   echo "Moving to new location /config/addons_config/prowlarr"
@@ -11,4 +11,4 @@ if [ ! -d /config/addons_config/prowlarr ]; then
   echo "Creating /config/addons_config/prowlarr"
   mkdir -p /config/addons_config/prowlarr
   chown -R abc:abc /config/addons_config/prowlarr
-fi
+fi