Step 2

<input type="hidden" name="appid" value=" 570 ">

<input type="hidden" name="consumer_app_id" value=" 570 ">

If you want to upload art and want to get rid of the game icons in any of the showcases, change the values to 760

Upload your artwork, fill in the title and description, you can change the game you're going to upload the workshop item for by doing right click > Inspect Element and expanding theby clicking the arrows in front of every line of code until you find these:You need toYou can find app-ids of games on https://steamdb.info/ Here's is a screenshot, right arrows show stuff that was not expanded and down arrows show stuff that was expanded: