My intention is so that once a player joins, the ROBLOX package ROBLOX Boy - Roblox is instantly displayed onto the avatar, however I am unsure how to exactly do this… Any suggestions?
You are unable to set it via properties because packages have been moved to bundles…
This should be an easy problem to solve. You see in studio, go to file > game settings > avatar > scroll down to body parts, you just need to copy and paste all the separate parts of the boy package by ID into these boxes and you should be able to spawn with these body parts loaded.
Feel free to change the scale of the character with the scale section which is just above body parts.