This request is similar to When asking a question notify users of similar questions except it applies to the Ask a Question button.

The Create from Template macro can be used to add an 'Ask a Question' button to any Confluence page.
To add the macro to a page:
In the editor, choose Insert > Other Macro.
Select Create from Template.
Enter the Button text, for example 'Ask a Question'.
Select Ask a Question from the Template Name drop down.
Skip the Title and Space Key fields - these only apply for page templates.
Choose Insert.
Your new Ask a Question button will take you to the same place as choosing Create > Ask a question.

When you go to Create > Ask a question there are no similar questions presented to keep you from opening a duplicate.