How can i add multiple tags from script?

I used @Xarbrough 's CustomTags script from his answer on this question:

But somehow i can’t comment there, because it seems like there is bug in that thread so i wanted to know how can i add a tag to any instance CustomTags List through script.

I have a character that shoots objects with a raycast, and upon contact i want it to tag the hit targets with “Hit” so i can group them for later use

Well, not being able to comment or reply on the other thread seems weird, but anyway: To add tags via script at runtime, you would simply need to extend the script and add a public method that adds into the list of tags.

public void AddTag(string tag)
    if (HasTag(tag) == false)