Low coolant

When we got our car (2015 Corolla LE) the coolant was on the low side in the reservoir but I didnt notice until after we bought it.

Now fast forward a year and 23k miles it's on the L

I don't want to pay for a coolant flush right now even though it's probably due so I want to just top it up till money isnt tight

Should i just add a few cups of distilled water or buy this coolant? I'm kinda weary about mixing coolant brands


Just double checked the coolant, it's actually at the same exact spot I just had bad lighting. So it isnt going down, but I kinda want to get it at least to the mid point