Completely untrue. DeSantis was asked this question many times, including as part of the official Florida gubernatorial debate, and never said he wouldn't run for President, and never promised to fulfill his term as Governor if he ran. His opponent Crist tried to make this an issue for the campaign, but failed. I live here and know, for sure.
Not from what I have read here on FR.
DeSantis doubles down on 2024 presidency stance: ‘It’s not anything that I’m planning for’
https://www.wtsp.com/article/news/politics/desantis-2024-presidency/67-93af4256-3f0a-4b6c-8c8a-82c666f957fe