Doenjang is a fermented soybean product from Korea that has a much stronger and more complex taste when compared with miso. Both are giving the sauce umami, so you really want to use one or the other. Sempio has a vegan doenjang. You can find it online or possibly at a local Asian Market, I bought mine at my local H Mart.You could replace the doenjang with miso. The flavor profile will be much more mild, but still tasty. If you use miso, consider using red miso.Other sweeteners can be used, I just like the flavor of the date syrup. Even dry ones like coconut sugar would work well.