Action Details
Requirements and how-to articles for itch.io's action:

As a creator, itch.io gives you the ability to design a page where people can download any projects you've uploaded. You can optionally put a minimum price on your page (which can be 0), giving people the opportunity to pay you what they think you deserve.

Requirements
You need this to get it done:

Title
The title of your project.
Project URL
You can customise the URL for your project. (By default, this is: https://[username].itch.io/[title])
Short Description or Tagline
Shown when itch.io links to your project. Avoid duplicating your project's title.
Classification
Select the type of content which you are uploading (Games, Game Assets, Game Mods, Physical Games, Soundtracks, Tools, Comics, Books or Other.)
Kind of Project
Select how your files can be run/downloaded (HTML, Flash, Java and Unity files can be embedded in your project page to be played in-browser, all other file types must be downloaded.)
Release Status
Select what the release status of your project is (Released, In Development, On Hold, Cancelled or Prototype.)
Pricing
You can choose from three different types of pricing for your project: $0 or donate, Paid, or No Payments. Note that your account must have payment configured if you want your project to be paid.
Project Files
You can upload your profile file(s) directly from your computer or from Dropbox. You can also add a link to an external file and itch.io will keep track of how many times it is downloaded. Note that the file size limit is 1GB.
Description
This will make up the content of your game page. Basic text formatting available, including image and video embedding.
Genre
Select the category that best describes your game (e.g. Action, Puzzle, Strategy, etc.) (You can pick additional genres with tags.)
Tags
You can add up to 10 tags to your project page - these are keywords which someone might search to find your project. Avoid using the genre or platforms which you already provided.
App Store Links
If your project is available on any other stores (Steam, Apple, Google Play, Amazon, Windows) itch.io will link to it.
Custom Noun
You can change how itch.io refers to your project by providing a custom noun. Leave blank to default to: 'game'.
Community
Choose whether you would like your project to have a comments section, a dedicated community discussion board, or none.
Visibility & Access
Choose whether your project page is a draft (only those who can edit the project can view the page), restricted (only owners & authorised people can view the page) or public (anyone can view the page.) By default, this is set to Draft, and it's highly recommended to keep it as Draft/Restricted until it is ready to be made public.
Cover Image
The cover image is used whenever itch.io wants to link to your project from another part of the site.
File format: .jpg/.png/.gif
Minimum dimensions: 315 x 250 pixels
Recommended dimensions: 630 x 500 pixels
Gameplay Video or Trailer
You can provide a YouTube or Vimeo link to either a trailer for your game or a video showing gameplay.
Screenshots
You can add screenshots of your game to appear on your game's page (this is optional but highly recommended.) Upload 3 to 5 for best results.
File format: .jpg/.png/.gif
Requirements missing or found errors? Report

How-To Articles
A list of useful links for you:

0
itch.io Documentation - Creator FAQ
FAQ for creators who upload their content on itch.io.
Official
Link missing here or found errors? Improve How-Tos