Bend rounded rectangle

Hi,

I need to create a line that would follow perfect circle for its length, 30% of the total circle. The line is thick 15-20 pixels, rounded ends. The color has to be a gradient.
Since I cannot apply a gradient to a line, I used rounded rectangle option.

Now... how do I "bend" this rectangle to make it follow a circle?

Here is an example how it should look like, no animation needed:

https://cdn-images-1.medium.com/max/1600/1*T480KKPWmIDxDD1KXPc-mQ.gif

or this, again no animation needed:

https://i.stack.imgur.com/im06K.gif

Thank you