By default, you can’t remove Attribution widget from Blogger, which renders Powered by Blogger text in your Blogger blog. Here’s how to remove this widget.
The Attribution widget appears in the layout section of your Blogger, but there’s no option to remove it. This trick will unlock the Attribution widget and an option to remove the widget will appear on the widget.
Go to your Dashboard > Template, click on Edit HTML, and search for this line:
<b:widget id='Attribution1' locked='true' title='' type='Attribution'>
Replace the word true with false to unlocked the widget, and save the template. Now, navigate to your Dashboard > Layout, click and edit the Attribution widget. Now, you can see the Remove button is there, click it.