Computed Attributes help

I have some Ruptela devices where I would like to have shown external power and battery power.

They are displayed in state, but as Io29 and Io30

Can I change it so that it says power instead of Io29 and Battery instead of Io30 or do new Attributes need to be made ???

Yes, you can do that using computed attributes.

Ok super.
I do not quite know what to write in Expression:
Could you possibly help me there?

There's plenty of documentation and examples, but if you don't want to research it yourself, we can always provide professional support:

https://www.traccar.org/product/professional-services/

would very much like to research it myself, but the examples I can see under https://www.traccar.org/documentation/computed-attributes/
I'm in doubt whether it can be used for this

I was lucky.
I found a thread with something similar where the author has shown what he had written

Ruptela ECO4 S
Power
io29 ? io29 : null
battery
io30 ? io30 : null

and it works.