Individual Lightning Lane access can be purchased through Disney Genie, part of the My Disney Experience mobile app. You do not need to purchase Genie+ to purchase Individual Lightning Lane; they are separate programs.
Guests staying at eligible Walt Disney World Resort Hotels will be able to purchase Individual Lightning Lane selections beginning at 7:00 a.m. on the day of their visit. All other guests will be able to purchase Individual Lightning Lane selections at the scheduled park opening time.
In Disney Genie, you can select the option to purchase a time to arrive at an attraction and be granted access to the Lightning Lane.
Once you select the attraction, Genie will guide you to select a time and your party. Only guests with valid tickets and Park Pass reservations can be added to your party.
Individual Lightning Lane options will show up on your Disney Genie Tip Board, allowing you to see which attractions are available.
For more on Disney Genie, check out the following articles.