Cronekorkn

hello everyone, i tried to create a modlet which went good so far but i want to add another tag at the progression xml. For example at the perk living of the land i want to add the tag chocolateseeds but i got no idea how to write that down. Do I have to use append, set or setattribute for this to work? And how does the line actually look if its done right. I tried a lot but coudnt figure out right typing.