Based on my journey, fasting happens naturally if it’s even supposed to.
When I first went keto, I was highly uncomfortable with the idea of skipping a meal, such as breakfast, much less OMAD 
the thought completely stressed me out - so I said ‘no, won’t do it’.
After, though, about 4 months, I got up one morning and was going to prepare breakfast, pretty much out of habit, and had a twinge of nausea and skipped breakfast, which has become pretty much a daily habit where for breakfast I have green tea & black coffee.
Then after about another 2 months on two meals a day, when I sat down to my dinner, the second meal of the day, I thought “gosh, I’m not really hungry, but I just love bacon and eggs so I’ll eat them.”
And this was a ‘revelation’ for me, illustrating the key benefit I’ve acquired on keto / ketovore / carnivore: my body and I now communicate quite well when it comes to hunger and food.
So after 6 months, I’ve pretty much moved to OMAD with 20 to 32 hours between each meal. However when I do actually feel hungry on some days, I will go for two meals. And I’ll even choose my meal based on my cravings: like if I’m thinking about fish and cod liver - I’ll make that for dinner, a baked chicken, bacon & eggs or just an all-dairy meal: cheese, cream and yoghurt, and I’ll eat until I get that first pinge of yuck, and I stop eating.
So, my suggestion is to take your time and go step by step and keep an ear out for a message from your body. Going on a low-carb regime (less than 20g / week) is such a shock as the majority of us have been running on significantly higher volumes of carbs and possibly with metabolic issues. Our bodies need time as they shift, heal and optimise.