Fasting is an interesting pratice, I did one time a week for 36h for some times, then settled on the 72h "when I feel I need it".
Rember to eat a lot of water and over the 24h you should be need to add some integrators (never did that, a friend alerted me about that and I still have to check which ones and if something natural, ex. salt, can be used).
And for the newcomers: feel your body/mind and don't overdo it 👍