Example of commutative Hopf algebra over the integers

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I'm looking for an example of a commutative Hopf algebra $H$ such that

  • $H$ is a torsion free $\mathbb{Z}$ module of finite rank

  • $H$ is not isomorphic to the dual of a group algebra $\mathbb{Z}G$

  • $H \neq \mathbb{Z}$

By commutative I mean commutative in the strict sense (i.e. xy = yx) and not in the graded sense.

I have been googling a lot, but couldn't find an example.