Can this recipe be made vegan by omitting the fish sauce? What can be substituted instead?

I wonder if a bit of kimchi liquid could be used?

Maggi Seasoning would work also. It is vegan, though not gluten-free.

Thai "thin soy sauce" aka "white soy sauce" is my preferred vegetarian fish sauce replacement. Dragonfly brand is by far the best I've tried. Many Asian food markets stock it, but here it is online: http://www.bangkokmarketusa.com/sauces/202-dragonfly-thin-soy-sauce-19-oz-.html

The fish sauce would have provided both salt and umami.
Think of substitutes which have those notes, including those mentioned so far.
Also/Or:
• fermented mushroom sauce
• pickle brine
• wine vinegar
• walnut ketchup

I would swap in miso paste or soy sauce instead, or if you have vegan worcestershire sauce (annie’s organics makes one) that’s another option

I think this recipe would taste good without the fish sauce too, just looking at the ingredients. But I can also see Smaug's point. It won't have the same funk as fish sauce, but miso paste would add some umami flavor place of the fish sauce.

I don't think you can just ignore fish sauce; it makes itself felt. Soy sauce is probably the best you can do; maybe something with one of those Chinese fermented bean concoctions, but I know little about them.

I'd just leave it out. Fish sauce gives salt and a little funk, but with those strong flavors, you won't miss it.