How would I transfer an item from server to client?

I've been battling the issue for a very long time and have been doing independent research in attempts of resolving it. Nothing I've found helps.

Basically, I'm trying to write a line of code where when the player clicks a button, the server transfers the gear from the StarterPack to the player's Backpack. Everything in the code works apart from the transfer.

If anyone knows a good solution, please send a response. It would be greatly appreciated!