How do you remove the dash before author's name

It is very hard to offer developers a donation when no support is given. If the developers really want a donation, then please assist in resolving my support question.

I have the same question.

If you go to the plugins section and click on edit you will see a list of files. I think this is the one you want to play around with :
quotes-collection/inc/class-quotes-collection-widget.php

I just had this problem and I solved it with custom CSS.

My problem:
Quotes displayed in a page using the short code had an extra dash and line space – but quotes displayed by the widget had the author and source formatted correctly, without an extra line space or em dash.

My diagnosis / solution:
I used Firefox’s inspector tool (you can use Chrome’s developer’s tools too) to figure out that this was caused by styling in my theme (Make) overriding the styling for the Quotes Collection plug-in. The plug-in uses the blockquote and cite tags to format the quotes and my theme added a line space and em dash to all cite tags within a blockquote.

Here are the theme styles that caused the problem.

blockquote cite {
	display: block;
}

blockquote cite:before {
	content: "\2014";
}

This is the custom CSS that solved my problem (your millage may vary, depending on your theme):

blockquote.quotescollection-quote cite {
	display: inline;
}

blockquote.quotescollection-quote cite::before {
	content: " ";
}