Once the single player mode has loaded, head to the interaction menu and select 'Director Mode'.Disconnect your internet while still on the phone, which should kick you off to GTA Online single player.
However, do not leave the screen where it says the vehicle has been! There are a fair few steps to it and some of them seem nonsensical, but it does work, so follow along carefully.
There are many versions of the frozen money glitch in GTA Online, but we're covering a recent version that still seems to work as of January 26, 2023.