How to make pagination in Pug?

Question

Pug

Good day!

For example, there are two files index.pug and login.pug, they expand different templates, when I run npm start, the index page opens with its template, this template has a link

li.nav-item.mx-10
    a.nav-link.br-10(href='/login') Default 2

But when clicked, the login.pug file with its template does not open.
Writes Cannot GET /login

Prescribed full let, also gives an error.

How to write paths correctly? And the page is opened from memory, and not the one that is generated (ondex.html) can affect it.

Please write with an example if possible.