I'm going to suggest you re-flash a stock ASUS ROM to your phone to restore that system app that you deleted. This will return your phone to a non-rooted status. Be sure to safely back up all your data first (and double-check that wherever you back everything up to that your files are there).
https://firmwarefile.com/asus-zenfone-max-z010d
Just curious but just why did you want to root your phone to begin with? It does allow you to do a lot more things with your phone, but as you've discovered it also enables you to mess things up in ways that you normally wouldn't be able to. Also, it enables one to totally brick their phone so it does need one to be judicious about what they do.
But if you want to root your phone again, I'd also suggest a couple of things.
-- Try using this rooting procedure involving Magisk:
https://www.maketecheasier.com/root-android-with-magisk/
Kingroot being a Chinese app with a dodgy history also includes a questionable privacy leaking process that runs in the background. Magisk is a safer alternative to use. If it doesn't work for you however, Kingroot might be what you have to use. in that case, since you will be rooted do have the ability to kill off that leaky background process.
-- Instead of deleting apps you don't want or need, a much better and safer option is to install an app like Titanium Backup. Along with being a backup utility it has a notable feature to allow you to 'freeze' an app, essentially disabling it. It's better to disable an app than delete it as if it's actually a vital part of the your phone's functionality if you disable it you can just re-enable it. Once you delete something like a system-level app, it's much more involved to restore it.
https://play.google.com/store/apps/details?id=com.keramidas.TitaniumBackup&hl=en_US