So frustrated with Hugo and themes. Is it just me ?

[submodule "themes/PaperMod"]
    path = themes/PaperMod
    url = https://github.com/adityatelange/hugo-PaperMod

Error: failed to load modules: module "PaperMod" not found in "/opt/buildhome/repo/themes/PaperMod"; either add it as a Hugo Module or store it in "/opt/buildhome/repo/themes".: module does not exist

module:
  imports:
  - path: github.com/adityatelange/hugo-PaperMod

hugo mod get -u

warning: adding embedded git repository: themes/PaperMod
hint: You've added another git repository inside your current repository.
hint: Clones of the outer repository will not contain the contents of
hint: the embedded repository and will not know how to obtain it.
hint: If you meant to add a submodule, use:
hint: 
hint:   git submodule add <url> themes/PaperMod
hint: 
hint: If you added this path by mistake, you can remove it from the
hint: index with:
hint: 
hint:   git rm --cached themes/PaperMod
hint: 
hint: See "git help submodule" for more information.