"Voters" doesn't always mean "eligible voters". "Those who cast votes in the election under discussion" seems a reasonable sense of the term in this context.
You are correct that he got the plurality and not the majority of the popular vote.
It is obviously not true that only 64% of voters who cast votes in the 2024 election cast votes in the 2024 election, so some meaning slipped here, somewhere.
You are correct that he got the plurality and not the majority of the popular vote.