So apparently since `next@13.4.x` they're using `undici` instead of `node-fetch` and that causes this error. There're plenty of GH issues related and it seems that it's not solved in next 14.0.3. https://github.com/vercel/next.js/issues/44062 https://github.com/vercel/next.js/issues/54961 I don't know how relevant this issue can be but posting instead someone else’s struggling with client functions like `createWebsite`. <img width="700" alt="Capture d’écran 2023-12-07 à 16 43 09" src="https://github.com/umami-software/api-client/assets/23030942/4f9a5b8a-22ea-4ccc-9401-e53f00e93280">