@@ -, +, @@ 
   choosing stocknumberAV.pl as plugin for subfield 952 $i.
   entry there, e.g. 'ABC', with any number in Description (eg. 123).
   If not set the framework accordingly.
   subfield.  You should see three dots on the right.  In the input field
   put ABC and click the three dots.
   be a message like:
   POST http://FQDN:8081/cgi-bin/koha/cataloguing/plugin_launcher.pl
   [HTTP/1.1 403 Forbidden 188ms]
   the 'ABC' (i.e. ABC 0000000124 or similar).
---
 cataloguing/value_builder/stocknumberAV.pl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/cataloguing/value_builder/stocknumberAV.pl	
+++ a/cataloguing/value_builder/stocknumberAV.pl	
@@ -50,8 +50,9 @@ my $builder = sub {
         function Click$params->{id}(ev) {
                 ev.preventDefault();
                 var code = document.getElementById(ev.data.id);
+                const token = document.getElementsByName('csrf_token')[0].value;
                 \$.ajax({
-                    url: '/cgi-bin/koha/cataloguing/plugin_launcher.pl',
+                    url: '/cgi-bin/koha/cataloguing/plugin_launcher.pl?csrf_token=' + token,
                     type: 'POST',
                     data: {
                         'plugin_name': 'stocknumberAV.pl',
--