To rewrite \( 9^{-23} \) using the property of negative integer exponents, we use the rule that states \( a^{-n} = \frac{1}{a^n} \).
Applying this rule to \( 9^{-23} \):
\[ 9^{-23} = \frac{1}{9^{23}} \]
Therefore, the expression with positive exponents only is:
\[ \frac{1}{9^{23}} \]