Final Fantasy IX was originally released in 2000 for the PlayStation 2. It has since been re-released on multiple platforms, including a mobile version, PC (via Steam), and most relevantly, the Nintendo Switch.
If you are looking for the Final Fantasy IX Switch NSP (JPN/USA) including the full update, here is everything you need to know about this definitive port. The Return of Zidane and Vivi on Switch final fantasy ix switch nsp jpn usa update full
Permanent Boosters: Options to instantly reach Max Level (99), Max Gil, and Max Ability Mastery. Note: These specific boosters cannot be disabled once activated. Version & Update Information Final Fantasy IX on Nintendo Switch Final Fantasy
The updates for Final Fantasy IX on Switch addressed several Day 1 issues, most notably: including a mobile version