Deploying to GH pages with Custom Jekyll Plugins - node.js

Question

I am trying to deploy a site to gh-pages. I am using this template. The side is a node built site with custom jekyll plugins.
My .yml is below.
name: Build and Deploy to Github Pages
permissions:
id-token: write
pages: write
on:
push:
branches:
- main
jobs:
build:
runs-on: ubuntu-latest
steps:
- name: Checkout 🛎️
uses: actions/checkout#v3
- name: Setting up Node
uses: actions/setup-node#v3
with:
node-version: '16'
cache: 'npm'
- run: npm ci
- name: Setting up Ruby
uses: actions/setup-ruby#v1
with: { ruby-version: '3.1.2' }
- name: Caching Gems
uses: actions/cache#v2
with:
path: vendor/bundle
key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile.lock') }}
restore-keys: |
${{ runner.os }}-gems-
- name: Build Site 🏗️
run: npm run install-jekyll
env:
NODE_ENV: production
- name: Upload artifact
uses: actions/upload-pages-artifact#v1
with:
path: "./site/"
deploy:
environment:
name: github-pages
url: ${{ steps.deployment.outputs.page_url }}
runs-on: ubuntu-latest
needs: build
steps:
- name: Deploy to GitHub Pages
id: deployment
uses: actions/deploy-pages#v1
Everything appears to run fine - no errors and GH tells me the site was deployed to zakraicik.github.io fine. However, when I visit the site- it shows 404.
Can anyone help me figure out where my mistake is? I assume it's somewhere in the .yml file.
The full repo is available here.