Multi language support / Routes.yaml not working

Hello,

I would like to add support for many languages on my blog. For this purpose, I have prepared the routes file. Unfortunately, the file, despite the configuration and setting of posts with the “pl” tag, does not work. The page is displayed empty. Another problem is changing the language on the website itself. do I have to make a separate collection and template for each language?

My routes:

routes:

collections:
/pl/:
permalink: /pl/{slug}/
filter: tag:pl
/:
permalink: /{slug}/
filter: tag:-pl

taxonomies:
tag: /blog/tag/{slug}/
author: /blog/author/{slug}/

Thanks!
Leszek