Hi,
I don't see any error notice or warning on that log. It looks like it's purely a apache access log and doesn't contain any PHP errors.
So unfortunately, it doesn't help.
Without the PHP error message it's hard to say what to do.
If you have any custom plugin / extension, or extensions integrated with HikaShop, try to disable them one by one and try each time if you still have the 500 error. That will allow us to narrow down a bit the issue.
But I would also recommend to check with your hosting how to display the PHP errors on the website instead of just a apache 500 error if they can't provide the PHP error log. That way, you would be able to directly see the fatal error message on the page where the problem happens.