When I walk, my legs are open. How can I correct my splayed leg?

My brother used to be like this,

But I specifically asked the doctor,

I don't remember the details. It was more than ten years ago, when I was young.

I remember sleeping with cloth or something.

Tie your legs together.

Then I stood against the wall with my legs tied during the day.

It's hard. At that time, my brother was young and I was young. It looks pathetic.