Itsme64's 1.20 Themed GUI V1 [1.2.1] is a release file of the Minecraft resource pack The Unnamed Update (1.20) Themed GUI, made for Minecraft 1.19.3. It was published on January 10, 2023 and is 3 MB in size. For the full description, screenshots and every other version, visit the The Unnamed Update (1.20) Themed GUI resource pack page.
How to install: Put the .zip into .minecraft/resourcepacks (do not extract it) and enable it under Options → Resource Packs.