My 2018 GMC Savana Wont Start

I have a 2018 GMC Savana. It was running well until yesterday. I filled the gas tank, got in it, and the damn thing wont start. The gas
gauge says "Gas Overfilled". I guess I must have put too much gas in the tank, which must make it not start. It wont even turn over. That light keeps flashing. How do I remove some gas?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.