Five substitutes will be allowed in League One fixtures in the 22/23 season

BUT:

A maximum of three opportunities are available to make substitutions during the fixture, plus an opportunity at half-time, but more than one substitution may be made at each of these opportunities.

The full EFL announcement:

https://www.efl.com/news/2022/june/number-of-substitutes-in-efl-league-fixtures-increases/