Have you tried restarting HA and seeing if that allows you to restart the configuration? Removing the integration and readding is also an option, as is restoring a recent backup.I can generate an owners API token ok. The problem I have is that I checked the ‘Fleet API’ box in the HA configuration to see what was needed and now I’m stuck in the screen that needs the additional Fleet API details.
My car might not even be on Fleet API but I can’t get back to the first screen to uncheck the Fleet API box. So at the moment I can’t try the owners API token.
Failing that, it looks like you may be able to modify the config/custom_components/tesla_custom/const.py file to revert the selection. I've not done this before so approach with caution.