Because 
Alexandria Lib runs quietly in the background without changing regular survival gameplay, you will not see any obvious signs of it when you load into a world. It does not add new blocks, items, or mobs on its own, so searching the Creative inventory or recipe book will return nothing.
Confirming the Mod Loaded
To make sure your mod loader actually recognized the library, check from the main menu before entering a world:
1. Launch Minecraft to the title screen.
2. Click the Mods button added by your mod loader.
3. Scroll through the list or type Alexandria into the search bar on the left.
4. Select the Alexandria Lib entry to confirm it is active in your current session.
What to Expect During Gameplay
Once you see it listed in the Mods menu, no further setup is required. Alexandria Lib acts purely as a central base providing shared helper tools for other add-ons. As long as your other mods start up without errors and their features work as expected inside your survival or creative worlds, Alexandria Lib is doing its job properly.