The name is there so that no two people can use the same online tickets.
Usually, the names are not checked at ticket controlls, however, they might be.
In the case it is just a typo or you forgot to put the second last name or something alike and it is clear that there is no intention to cheat the system, the ticket controll would most likely not be overpedantic but if it is completely wrong and your name gets verified you might run into issues.
Note that you can refund the ticket and buy a new one without any costs if you bought a regular ticket and the time frame during which it is valid has not yet begun.