For a while, I have been experimenting with NBT Data on minecraft. Recently, I wanted to make a fox that trusts both me and a friend of mine, and I know this is possible, as they have the tag "TrustedUUID"
 However, I don't know how to use it. There are no tutorials about using this tag, and the Wikipedia, while mentioning it, does not give a good explanation. How can I use this to make a fox that trusts me and my friend?
 I have tried to use only my friend's UUID, which did not work. I saw something about "M" and "L," but do not know how to use them. Is there any possible way to do this?