There are two possibilities as to why you get stuck on the loading screen. Either your game's files are corrupted, which can sometimes happen with an incomplete update, or you're not running the latest version of Apex Legends. Well, you can try this out:
- Restart your internet.
- Verify game files. Launch Steam. Right-click on Apex and choose “Properties.” …
- Check server status.
- Run Apex Legends as Administrator.
5. If all else fails, try uninstalling and reinstalling the game
> This useful and full-scale guide helped me a lot in resolving the issue
[SOLVED] Apex Legends Infinite Loading Screen (3 Easy Fixes!)