That's it. Eyeball it. It costs pennies to make.
All the animal products are microscopic amounts in the "beef" and "chicken" bouillon cubes, they ALL contain yeast extract, salt, onion powder as 99% of their composition.
You obviously don't need any of the animal products but you don't need any of the preservatives, sugar and corn solids either.
Be free from Big Stock and Big Bouillon who have been lying to you all this time.
In Australia a brand makes a low fodmap vegan stock powder. It tastes identical because it is. They just remove the animal products that are there for labelling purposes.