I lost 15kgs in the pandemic as I was turning 50 and decided I didn't want to be fat and 50.

The only way I did it was to log all my food and keep to a calorie limit every day. I get people that ask me how I did it all the time and I tell them I ate less food and they all look disappointed like I was going to tell them some magic trick. I've managed to keep the weight off by really only eating one meal per day, in the evening.

Exercise is good and important in itself but it won't help you lose weight, outside of extreme levels of activity.