How can I permanently hide in-game chat in Roblox?

Hello all, I am far from a programmer but I understand some basics and can follow directions. My problem is that I have found that some of the in-game chatting I have seen while my 7 year old is playing Roblox games is inappropriate for her. I have searched for ways to edit the GUI and hide the chat and I believe I found what I am looking for. A Roblox guide said to insert this code: game.StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Chat, false) and chat will be hidden.
I watched a couple videos and went into Studio, logged into her acct and inserted that line and indeed it worked when I went to test the game.
My problem is how the heck do I save that code so it will apply to the games outside of Studio? When I get on her ipad or my pc under her acct the chat is still there. I am missing something but I am having a tough time figuring it out. Any help will be greatly appreciated, thank you!

It's impossible to disable the chat system in others' Games with code, and it is also no longer possible to disable the chat via account settings.

The best you can do is edit the account's settings and set their birthday so their age is less than 13, which enable the strictest chat setting ROBLOX has.

People will still go out of their way to abuse this system and avoid the filters, enabling the inappropriate content you've seen, and I'm afraid there's no way to avoid that. It'll happen in any online game she plays. What I suggest is to using the in-game and website Reporting systems to let ROBLOX know that these users are violating the rules by saying inappropriate things. This will help ROBLOX improve the filters, and remove abusive users from the site.

You can email info@roblox.com with a request to have more restrictive privacy settings enabled for your daughter's account, but it's likely they can't do anything either.