This collection is part of the lab namespace.
If this wasn't installed by cloning https://github.com/suppaduppax/ac_lab then ensure that the collection is cloned inside the collections/lab directory inside your ansible collections directory to keep documentation consistent.
Install as a submodule into your ansible project's collection's lab directory:
Create the collections directory
mkdir -p collections/lab
Change to the directory you just made
cd collections/lab
Add the submodule in the lab collection, renaming the ac_lab_common repo to common
git submodule add ssh://[email protected]/suppaduppax/ac_lab_common.git common