Ive looked around on the internet but all I could find was a developer forum post I don't understand.
If someone could explain to me what I need to use or do a step-by-step tutorial it would be a huge help. Thanks.
It is possible.
First of all, you need the player module. You can get it by joining your game on ROBLOX Studio and going to your player's 'Player Scripts'. Once you have located it, copy it and end the play-test session.
Then, paste it into StarterPlayer>StarterPlayerScripts. Once you have done that, uncollapse the module and you should find the module, 'CameraModule'. Once you have found that, uncollapse the 'CameraModule' and you should be able to find 'MouseLockController'.
Double-click it to edit it and keep scrolling until line 41 where you will find the keybinds. Edit them appropriately or replace the whole line with this:
boundKeysObj.Value = "LeftShift,RightShift"
Replace the keycodes with your own (e.g. LeftControl). If you have more than 1 keybind, remember to separate them with commas!
If this helped you, please mark this question as solved!
I think its impossible. You can only disable shift lock by disable EnableMouseLockOption in StarterPlayer