how i can read the codex entries?

Also in bf1 website, just log in, you can also check your progression online, which doesn't show up on the app.

On the Battlefield website, just log in and click the "career" tab in the top left corner.

From there, choose Battlefield 1, then you can see the "Codex" tab on the top right:

@robertgamer250

If you play Battlefield 1, you can simply go In-game to your Soldier Tab and click on "Codex". There you can see all of them, how far you'r with unlocking them or you can read a Story from this Codex Entries which you have already unlocked.