It won’t work.
Look here https://gilholm.dk/page-4/#stacks_in_23_page6_collapse
Hi @npfs welcome to the forums.
I’ve checked your source code and you are not using the Foundry Theme, please make sure you use the Foundry Stacks with the Foundry Theme.
You can download a copy here: https://foundry.elixirgraphics.com/release-notes/