Use this app on base path url

[kantium]

Hello,

I would like to use this app on a sub url like https://exemple.com/explorer/
I setup this app with an nginx reverse proxy. The proxy work, and I gan get the index page,
but every link are wrong and goes to https://exemple.com/block instead of https://exemple.com/explorer/block

I tried but I'm unable to (and don't have enough knowledge) to edit the app.js file successfully.
I tried to put a router with var router = express.Router();
and edit all routes to router.use('/block', block); and finally make the app use app.use('/explorer', router); but it's not working.

Could someone help me ?
Thanks

Nginx config

location /explorer/ {
                proxy_set_header Host $host;
		proxy_set_header X-Forwarded-Host $host;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header X-Forwarded-Proto $scheme;
                proxy_redirect         off;
                proxy_pass http://localhost:3000/;
}