The REDMI Watch 5 does not support downloading third-party Apps. Going to [Settings] >> [Apps] on the watch will not allow you to download third-party software.
If you accidentally delete a pre-installed app, such as Alarm, you can restore it through the following path:
[Settings] >> [Apps], click [Manage apps] >> [System apps], find the accidentally deleted or uninstalled app, and select [Install] to reinstall it.