Solution:

The answer is 1348. If the knaves are odd in number, say $2m+1$, then the people who tell the truth are all and only those in odd positions less than or equal to $2m+1$, which are $m+1$. There would then be $2m+1$ knaves and $m+1$ knights, for a total of $3m+2$ people, but this is impossible since the equation $2023=3m+2$ leads to $m=\frac{2021}{3}$, which is not an integer. The knaves are therefore even in number, say $2m$: the knights will be all and only the people in odd positions less than or equal to $2m$, plus the person in position $2m$, hence in total $m+1$. Thus $3m+1=2023$ and therefore the knaves are $2m=1348$. One verifies that the configuration works.