Cara eu acho que o middleware do nextjs pode fazer isso, no react eu faço usando axios eu uso o interceptors.request.

import axios from 'axios';
const instance = axios.create({
baseURL: window.location.hostname === 'localhost' ? 'http://localhost:5001/api/v1' : 'https://api.mysite.com/api/v1'
});
instance.defaults.headers.common['Content-Type'] = 'multipart/form-data';
//validate response
instance.interceptors.response.use((response) => {
return response;
}, (error) => {
if (error.response.status === 401) {
return window.location.href = '/login'
}
return Promise.reject(error);
});
// Set the AUTH token for any request
instance.interceptors.request.use(
(config) => {
const token = localStorage.getItem('token');
config.headers.Authorization = token ? Bearer ${token} : '';
return config;
}
)
export default instance;