Ansible bigip_commands module and Bash

I'm hoping this is a simple question. I'm trying to use ansible to check for the presence of some files on a Big-IP. I've tried using the bigip_command module to call commands like grep and file, but I can't get it to run any bash commands, only tmsh. The description says "bigip_command – Run TMSH and BASH commands on F5 devices". How do I get it to run Bash commands? I must be missing something.

Thanks in advance!

https://clouddocs.f5.com/products/orchestration/ansible/devel/modules/bigip_command_module.html