[Q] Trying to get return values in ui and console

i started using comfy ui, but im trying to do something basic not sd related, im having trouble showing a simple return value in the ui.
I already checked different examples but i dont get the output part...
```python
class Add:
@classmethod
def INPUT_TYPES(cls):
return {
"required": {
"a": ("FLOAT", {"default": 1.0}),
"b": ("FLOAT", {"default": 1.0}),
}
}

RETURN_TYPES = ("STRING",)
FUNCTION = "calc"
OUTPUT_NODE = True
OUTPUT_IS_LIST = (True,)

CATEGORY = "math"

def calc(self, a, b):
c =str( a + b)

return ( c,)

```

i dont want to manually print the return values in the classes above.
in the server im trying to see the return value:

```python
@routes.post("/prompt")
async def post_prompt(request):
print("got prompt")
resp_code = 200
out_string = ""
json_data = await request.json()
json_data = self.trigger_on_prompt(json_data)

pp(json_data)
```

im trying to see text return values inside the nodes. i tried a ShowText node no success.
can someone please point me to what im doing wrong...