It looks like to me, and I'm no expert that this can just be a failure to authenticate? The error message is misleading, or actually meaningless, at least to me. I would guess from the error message that the IDRAC version is not supported though any failure here that would result in idrac being none will produce the same error message.
https://github.com/anupamaloke/Dell-EMC-Ansible-Modules-for-iDRAC/blob/9fdeb2331563b793c73eb7618170379637a4633d/utils/dellemc_idrac.py#L73
It looks like to me, and I'm no expert that this can just be a failure to authenticate? The error message is misleading, or actually meaningless, at least to me. I would guess from the error message that the IDRAC version is not supported though any failure here that would result in idrac being none will produce the same error message.