Because the American population is 3 times what it was in 1918 likely we should expect around 3 times the deaths then

 It is estimated that about 500 million people or one-third of the world's population became infected with this virus. The number of deaths was estimated to be at least 50 million worldwide with about 675,000 occurring in the United States.

end partial quote from:

History of 1918 Flu Pandemic | Pandemic Influenza (Flu) | CDC

Here's the problem:

Instead of losing 50 million to coronavirus this time we likely will lose at least 3 times that much or 150 million people by 2022 from coronavirus worldwide. This tally likely won't fully become known until 5 to 10 years from now because of a variety of reasons worldwide.

Here in the U.S. we should expect three times the 650,000 to 675,000 lost from 1918 to 1920 here in the U.S. as well which would be about 2 million  to 2,025,000 deaths by 2022.