I had to look it up. I thought it was a common product, but apparently it's Indonesian, so that's why it's common in the Netherlands (our dark colonial history) but not internationally.
It's an Indonesian soy sauce. I found a wiki page with 14 languages, including Dutch, but not English xD
Here's the Deepl translation:
Ketjap (Indonesian: kecap) is an Indonesian soy sauce. It is made from a fermented mixture of soybean flour, coarsely ground wheat, spices, sugar, and salt.
There are many types of ketjap, including:
Ketjap manis: very sweet soy sauce
Ketjap sedang: less sweet soy sauce
Ketjap asin: salty soy sauce
Ketjap kendal: dark, syrupy soy sauce; similar in taste to ketjap manis
Ketjap medja: dark, syrupy soy sauce; sweet and salty. Its flavor is between manis and asin
Ketjap asin is used in the kitchen when preparing dishes, while ketjap manis is used at the table as an addition to flavor a meal. Ketjap manis is the most commonly used type.
Indonesian ketjap is characterized by its dark brown color and syrupy consistency. This differs from Chinese and Japanese soy sauces, which are thinner and usually not sweet.