If you don't want to see the Pop-up button when you select a text with the mouse, you can hide the button on the Pop-up Bubble Translator.
Clear the checkbox next to the Translator's button. This will temporarily disable the Pop-up button which appears next to the selected text.
If you want to permanently disable the Translator's button, clear the checkbox next to the "Show Translator's button" in Pop-up Bubble Options.
The ImTranslator button will no longer appear when you highlight the text on a webpage.
To run the Pop-up Bubble application, use the context menu or the shortcut (Alt).