Hi @meneldil
I’m afraid this is not possible. You need to modify the core files to do that. You can check how it works in “wp-content/plugins/advanced-custom-fields-pro/pro/assets/js/acf-pro-input.js”, but you need to apply the modification in “wp-content/plugins/advanced-custom-fields-pro/pro/assets/js/acf-pro-input.min.js”.
Thanks 🙂