I would like to track not only proteins, carbohydrates, fats, but also sugars, possibly other nutrients. Is this possible?

iOS and Android

Yes, with the Premium version. In addition to basic nutrients, you will also have graphs for sugar, salt, calcium, saturated fatty acids and PHE. After purchasing a Premium subscription, you can enable them in More (☰): Custom settings

WEB

Yes, with the Premium version. In addition to basic nutrients (proteins, fats, carbohydrates), you will also have graphs for other nutrients (sugars, salt, calcium, saturated fatty acids and PHE). After purchasing a Premium subscription, you can enable these graphs in the Settings tab in the left side menu on the page → Custom nutrients.