Abdominal Exercises

Hello, I have come across pictures and articles on the Internet about 30-day challenges for tightening legs, abdomen, ass, etc. These challenges are 3-4 exercises that are done every day and gradually increase their repetition. I am of normal weight compared to my height, but I have a belly from which I have to remove about 7 cm. I did various exercises for several months, I changed them every 15 days, not to get used to them, I was careful what I ate and nothing. I lost only 1 centimeter. Later I was told that I had to lose 2-3 kg and then tighten, because the muscles develop and "push" the fat forward, ie my abdomen looks even bigger. I stopped doing them, now I only do those for the legs, I started trying to take them off, but I'm probably used to them, because sometimes I can't stand it and I do some abdominal presses. So, my questions are, do you think I should download first or look for some more difficult workouts? I am also interested, if someone has done such a 30-day challenge, what was the result and shouldn't there be a break, shouldn't 30 days of doing it constantly be harmful for the muscles? I know I wrote in confusion, if I could express myself better I would. I know, and that many similar topics, I read a lot, but none was of much use to me. I'm sorry if I made mistakes, I write from the phone. PP Please let the moderators post the topic. that I wrote confused, if I could express myself better I would. I know, and that many similar topics, I read a lot, but none was of much use to me. I'm sorry if I made mistakes, I write from the phone. PP Please let the moderators post the topic. that I wrote confused, if I could express myself better I would. I know, and that many similar topics, I read a lot, but none was of much use to me. I'm sorry if I made mistakes, I write from the phone. PP Please let the moderators post the topic.