добавил строчку
res.set('Access-Control-Allow-Origin', 'http://localhost:3000');
const app = express();
app.get("/api", (req, res) => {
res.set('Access-Control-Allow-Origin', 'http://localhost:3000');
res.json({ message: "Hello from server!" });
});
вот какие ошибки выдает
3000/api. URL scheme "localhost" is not supported.
(анонимный) @ App.js:9
commitHookEffectListMount @ react-dom.development.js:23150
commitPassiveMountOnFiber @ react-dom.development.js:24926
commitPassiveMountEffects_complete @ react-dom.development.js:24891
commitPassiveMountEffects_begin @ react-dom.development.js:24878
commitPassiveMountEffects @ react-dom.development.js:24866
flushPassiveEffectsImpl @ react-dom.development.js:27039
flushPassiveEffects @ react-dom.development.js:26984
(анонимный) @ react-dom.development.js:26769
workLoop @ scheduler.development.js:266
flushWork @ scheduler.development.js:239
performWorkUntilDeadline @ scheduler.development.js:533
App.js:9
Uncaught (in promise) TypeError: Failed to fetch
at App.js:9:1
at commitHookEffectListMount (react-dom.development.js:23150:1)
at commitPassiveMountOnFiber (react-dom.development.js:24926:1)
at commitPassiveMountEffects_complete (react-dom.development.js:24891:1)
at commitPassiveMountEffects_begin (react-dom.development.js:24878:1)
at commitPassiveMountEffects (react-dom.development.js:24866:1)
at flushPassiveEffectsImpl (react-dom.development.js:27039:1)
at flushPassiveEffects (react-dom.development.js:26984:1)
at react-dom.development.js:26769:1
at workLoop (scheduler.development.js:266:1)
(анонимный) @ App.js:9
commitHookEffectListMount @ react-dom.development.js:23150
commitPassiveMountOnFiber @ react-dom.development.js:24926
commitPassiveMountEffects_complete @ react-dom.development.js:24891
commitPassiveMountEffects_begin @ react-dom.development.js:24878
commitPassiveMountEffects @ react-dom.development.js:24866
flushPassiveEffectsImpl @ react-dom.development.js:27039
flushPassiveEffects @ react-dom.development.js:26984
(анонимный) @ react-dom.development.js:26769
workLoop @ scheduler.development.js:266
flushWork @ scheduler.development.js:239
performWorkUntilDeadline @ scheduler.development.js:533
Promise.then (асинхронно)
(анонимный) @ App.js:9
commitHookEffectListMount @ react-dom.development.js:23150
commitPassiveMountOnFiber @ react-dom.development.js:24926
commitPassiveMountEffects_complete @ react-dom.development.js:24891
commitPassiveMountEffects_begin @ react-dom.development.js:24878
commitPassiveMountEffects @ react-dom.development.js:24866
flushPassiveEffectsImpl @ react-dom.development.js:27039
flushPassiveEffects @ react-dom.development.js:26984
(анонимный) @ react-dom.development.js:26769
workLoop @ scheduler.development.js:266
flushWork @ scheduler.development.js:239
performWorkUntilDeadline @ scheduler.development.js:533