Hey - I had done all of this.
The solution - which is not in the video, or in the docs - was to add it to the generated types declaration file inside .slicemachine into the .tsconfig
{
"extends": "tsconfig/nextjs.json",
"include": [
"next-env.d.ts",
".slicemachine/prismicio.d.ts", // here
"**/*.ts",
"**/*.tsx",
"**/*.jsx"
],
"exclude": ["node_modules"],
"compilerOptions": {
// ... your config
}
}