My animation doesn't work, why?

Question

<! - - My code - - >
<svg width ="100" height="50">
<circle cx ="10" cy="10" r="10">
<animate attributeName="x" from="0" to="300" dur="3s" fill="remove" repeatCount="2"/>
</circle>
</svg>

<!-- --Example of sololearn-->
<svg width="1000" height="150">
<rect width="150" height="150" fill="orange">
<animate attributeName="x" from="0" to="300"
dur="3s" fill="freeze" repeatCount="2"/>
</rect>
</svg>
<!--My html animation doesn't work, why?
It's written as the example of Sololear
The code you can see in my profile -->
https://code.sololearn.com/WNtwwjm512PV/?ref=app

Answer 1

For circle attributeName should be cx not only x.

Answer 2

Oh... Thanks!