Strangely enough, this type of thing worked:
for node in $Labels.get_children():
"TEST_LABEL":nodes.set_text("Cheese with Peanut butter.")
I tried every method mentioned in the answer and some other of my own, but my project didn't liked any. I don't know the reason, it remained a mystery to me.
Also I didn't fully prompt the error, going to put it here,
0:00:00.840 get_node: Node not found: TEST_LABEL.
<C++ Error> Condition ' !node ' is true. returned: __null
<C++ Source> scene/main/node.cpp:1381 @ get_node()
<Stack Trace> Status_UI.gd:18 @ STATUS_UPDATE()
Status_UI.gd:14 @ _ready()
And here is the line of code on ready.