En nextjs podemos tener barras de progreso de dos formas, la primera es usando bibliotecas genericas como nprogress y la otra usando bibliotecas que ya se integran con nextjs como next-progress-bar
https://www.npmjs.com/package/nprogress https://gist.github.com/sergiodxa/2733d1922853a4c3593e668eb2fc4ceb
https://github.com/Skyleen77/next-nprogress-bar https://www.npmjs.com/package/next-nprogress-bar
Otros Recursos
https://github.com/apal21/nextjs-progressbar/blob/master/src/index.js https://medium.com/@apalshah/next-js-how-to-make-your-own-progress-bar-indicator-component-easily-445e58777473 https://www.gosink.in/next-js-make-your-own-progress-bar-indicator-component-easily/ https://www.npmjs.com/package/nextjs-progressbar