iFrame errors in React app

I have a frontend written in React. If I am initializing Sentry, I will get the errors in React. However, I have iFrame with nodejs/typescript/webpack running. From the frame app, I am not getting any errors. I am sure that I have them there. ErrorBoundary is not helping also. ‘onerror’ for iframe element is not giving anything. Could someone provide information on how can I solve this issue?