depending on是分词短语做定语还是状语

请问老师depending on是分词短语做定语还是状语？

There's a flat fee depending on your diet.

There's a flat fee depending on your diet.

作 flat fee 的定语，缘由是 there be 存在句表示状况，be 不是行为动词，所以分词短语只能作定语。除此之外它的逻辑主语是 flat fee，也可以说明这个问题。

There's a flat fee depending on your diet. 等于 There's a flat fee which depends on your diet.