The taste is a bit more of a lighter, refined type of Asian bouillon. It comes in powder (bag), paste (in a tube) and solid (in a can) form and looks like the solid version can be purchased via Amazon in 250g and 1kg portions
https://www.amazon.com/Foods-Shantung-Deluxe-Chinese-Soup/dp/B07RK75B5Z
https://www.amazon.com/Shokuhin-Shantan-Deluxe-Vegetable-Extract/dp/B003T3C256
Either of the Lee Kum Kee Bouillon's are more easily found in Asian supermarkets and might be a substitute but I haven't tried them so can't say for sure.
https://www.amazon.com/Lee-Kum-Kee-Chicken-Bouillon/dp/B0001DMTNC
https://www.amazon.com/Lee-Kum-Kee-Bouillon-Flavored/dp/B08976Q7R1