You have to do it on a computer. The teacher application does not work on a mobile phone.

Thank you so much

I dawnload the app but i din't found the button.

<a href="https://teach.italki.com/application" rel="noopener noreferrer" target="_blank">https://teach.italki.com/application</a>;

Click Community -> Articles.

There is a box on the right "become a teacher"