Question:
Shalom, is it allowed to use a plata that has time (that can be programmed to turn off and on at shabbes)?
Answer:
Here are a number of links to various questions on this topic that were discussed in various posts.
Best wishes
https://dinonline.org/2011/02/03/shabbos-hatmana-returning-food-to-heat-on-shabbos/
https://dinonline.org/2020/08/02/platta-on-shabbos-timer/