Help about main image

Where i can found the url of main image?
I have only a thumb of 200px
I try to modify the config thumb image.... but nothing work
Please help

Fabio

1. Open plugin Configure page (page with serial number).
2. "Article thumbnail image size"  - picture size for all articles.
3 If you plan to use RSS, you can change "Newsline. Article thumbnail image size" too