[Closed] translate custom code

Background of the issue:
I want to translate some content I have added to my products with custom code on my site hidden link. I am following the documentation at https://wpml.org/documentation/support/language-configuration-files/translate-custom-shortcodes-with-wpml/.
On some of the products, the value is 0 (I think the variable products). On the simple products there is no value. See the screenshots. I am talking about the price per litre.

Symptoms:
I need help translating custom code content.

Questions:
How can I translate content added with custom code using WPML?