I'm not sure how to check my camera's firmware version. I tried booting the other two versions separately as well, but none of them worked. However, for 1.0.2, a screen appears after I press the OK button, displaying the CHDK version for about 2 seconds before it shuts down again.
This means 102a is the correct version, but it's crashing after CHDK loads
As caefix suggests, this port has a known problems with the "firm update" booting method and you can try the "bootable SD card" method instead https://chdk.fandom.com/wiki/Prepare_your_SD_card
To use this, you'll need a card which is formatted FAT32. By default, cards larger than 32GB will be formatted exFAT, which these cameras cannot boot from. While you could probably format your 128GB card FAT32, you cannot do it in camera or easily on windows without 3rd party tools. Getting a cheap 32GB card for CHDK may be the most straightforward approach.