Subgroups of $\mathbb{Z}^*_n$

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I am trying to write a code using SAGE to find all subgroups of $\mathbb{Z}^*_n$ where the elements of subgroups are elements of $\mathbb{Z}_n$.

To elaborate, when I am using the command .subgroups(), it returns the subgroups in generator-relator form and not as integers. Is there anyway to do it?