COLUMBUS, Ohio (WCMH) — New details are emerging about the process behind the Vax-a-Million drawing that will generate its first winner on Wednesday, May 26.

The Ohio Department of Health says The Ohio Lottery will use a random number generator for the drawing. A video of the process is posted on the department’s YouTube Channel.

Sunday at 11:59 p.m. is the deadline for vaccinated Ohioans to enter the drawing. ODH says not all Ohioans who are eligible have entered — about 5.1 million people.

Instead ODH estimates the number of Ohioans who have opted-in to the drawing at about a million.

All Ohio residents who have had at least one Pfizer, Moderna or Johnson & Johnson shot are urged to register at Ohiovaxamillion.com or by calling 1-833-4-ASK-ODH (1-833-427-5634) before 11:59 Sunday night to be eligible for the first drawing.

The Ohio Department of Health says Ohioans only need to register once to be eligible for all five drawings, which will take place at 7:49 p.m. on each Wednesday through June 23.