Arrow text centering on line

Hi Aleksey! 

Thanks for posting in our community! The shape that you're using is called a decision shape. When you use connectors to connect these shapes together a text box is automatically placed centered on the line for you to write in. If you would like to post text above or below the line you can simply insert a text box onto the canvas and place it above or below the line. But when using decision shapes. you will always be given an automatic text box in the middle of the line for you to edit. 

I hoped this helped! Feel free to reach out if something didn't make sense or if you need some more help!