Quick question, lets say I am running an growthbook instance in the server, and I go and change the traffic split for the test. How would this instance know that the traffic split changed? Does the library gets updated automatically for this cases?

When you publish changes to a feature, the /api/features/ endpoint gets updated with the latest configuration and we send out a webhook (if you have one enabled). How your application gets updated depends on how you integrated (caching layers, etc.)

so we need to set this up then I see

People tend to either poll the /api/features endpoint periodically and update a cache OR they add a webhook to update a cache. Then, have the SDKs read from the cache

So I found in the website the webhooks, now I just need to provide an endpoint there in order to update in the server. But now I need to figure out the frontend part also

There are docs here if you haven't seen these yet - https://docs.growthbook.io/app/webhooks

after finding in the website it was pretty obvious 🙂 Thanks for the help again Jeremy, I already created an endpoint here for the webhook