In order to customize your Wordpress page there is a file in the plugin where you can add all the css code you want.
To get to the file it is necessary to follow the following steps:
First, go to WordPress admin area and visit Plugins. In this page, show all the plugins installed. Find the uvwpintegrations plugin and click Edit.
The Plugins Editor Screen allows you to edit those Plugin files.
Click on uvwpintegrations/uvcustom.css file. You can see that the file is empty.
In this file you can add all the css code you want. Once you have added the code click on Update File.
Examples of how you could see a custom css: