How to deploy a svelte project to github pages on custom domain

do quick start at bottom of this page https://github.com/metonym/sveltekit-gh-pages

in github settings/pages change default branch to gh-pages

add custom domain

in code tab switch to gh-pages

in svelte.config.js switch base to
base: process.env.NODE_ENV === “production” ? “” : “”,

yarn build
yarn deploy

ask chat GPT if you get stuck