SSG on nextJS when appRouter is made with fastify adapter?

export const getStaticProps: GetStaticProps = async () => {
const ssg = await createSSGHelpers({
router: appRouter //This app router is in fastify
ctx: await createContext(),
});

await ssg.fetchQuery("personalStats");
await ssg.fetchQuery("ageOfOnsetPsychosisByGender");
await ssg.fetchQuery("PsyLengthByGender");

return {
props: {
trpcState: ssg.dehydrate(),
},
revalidate: 1,
};
};
export const getStaticProps: GetStaticProps = async () => {
const ssg = await createSSGHelpers({
router: appRouter //This app router is in fastify
ctx: await createContext(),
});

await ssg.fetchQuery("personalStats");
await ssg.fetchQuery("ageOfOnsetPsychosisByGender");
await ssg.fetchQuery("PsyLengthByGender");

return {
props: {
trpcState: ssg.dehydrate(),
},
revalidate: 1,
};
};
Anybody used next SSG with fastify adapter? If try to import appRouter from fastify to getStaticProps router in nextjs, I get webpack loader problems. How should I approach getting this to work?