Java script error

hey there,

my website is produciny an error I am not sure what to do about. Looking at the site with Chrome and inspect mode/console, an error message is shown:

JQMIGRATE: Migrate is installed, version 1.4.1

wp-lists.min.js?ver=5.1.1:1 Uncaught ReferenceError: ajaxurl is not defined

at wp-lists.min.js?ver=5.1.1:1

at wp-lists.min.js?ver=5.1.1:1

I googled it but couldn't find anything useful.

Kind regards

Johannes