Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
There is nothing wrong if someone were to take the shahadah in a state of impurity or while exposing the awrah.
Responding to the question in point, Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
Although it would be most desirable to recite the shahadah in a state of purity while wearing a modest attire, there is nothing wrong if someone were to say it in an impure state or while exposing the awrah.
Since there is no evidence in the sources to stipulate that; otherwise, it cannot be judged as haram; we can only say it is undesirable to do so.
For more, see these fatwas:
Should You Delay Shahadah Due to Parents Objection?
Do You Need Witnesses to Take Shahadah?
Do New Muslims Have to Say Shahadah in Public?
Almighty Allah knows best.