What do you mean by "capture the credits" ?
The trainer i used has a feature called “capture credits”.
“Capture Credits - You must use this FIRST before the Set Credits
option will work. To use this, you must be driving in the car.
Stop the car, and then press the option key and then press the ESC key to
enter the World Map and Menu Window. You can see your Credits value
at the upper right of the screen. Then you can use the Set Credit option
below to set the credits.”
“Set Credits - Make sure you have used the Capture Credits properly
first, then press this key to set it to the value shown in the trainer.
You will need to start an event, buy something, earn Credits, or do
something that causes the game to save the data for it to Stick”