“advice” is an uncountable mass noun in English like "water". Remove the "a", and "another". Theses imply singularity. - That's good advice. - I have more advice more you. (more desirable) I have extra advice for you. (still correct, but less desirable)

That's good advice. I've some additional advice for you - For extra I've differing advice for you - In contrast to if an advice has already been imparted. Thanks : )