How can I transfer text from a local PlayerGui textbox to a Serverside value?

I'm trying to make a script that takes text from a textbox that is inside someone's PlayerGui. I understand that you need a local script to access a PlayerGui, but transferring text from a textbox inside a player's GUI to values in ReplicatedStorage works, but is only client-side since the script is a local script. I don't know how to take text from a client-side GUI and transfer it into stringValues server-side wise. Any answers?