Did you install it correctly?
https://www.trovesaurus.com/page=625/manually-installing-mods
https://www.trovesaurus.com/page=1136/installing-mods
Have you tried reinstalling the mod?
which Trove are you using, the Steam version or the Glyph version?
Perhaps you have another mod for the Dracolyte so it's ignoring the "Undertale sans for dracolyte". I don't think you can have 2 mods for the same item because the other one will get ignored.
Using a modloader makes handling your mods easier.
http://forums.trovegame.com/showthread.php?101283-Mod-Loader-amp-Guide-Trove-Mod-Manager-Hosted-by-Trovesaurus
https://dazotrove.github.io/TroveTools.NET/