See this article on how to edit your submission. Below are some specifications about the different presentation material you can upload.
Poster
The poster needs to be:
Image format (jpeg, png, gif or PDF);
Maximum of 100 Mb;
The landscape format is ideal, but the portrait format will work as well.
There are no specific dimensions, but as a matter of comparison, something like 16 x 9 would work.
Note: If you upload a PDF with multiple pages, the first page only will be converted into an image.
The poster will appear full screen in its tab. Buttons will be visible to zoom in and out. You'll be able to scroll through it using the mouse.
Slides (Powerpoint)
The Slides field uses the Microsoft Powerpoint online viewer which accepts:
A Powerpoint format (.ppt, .pptx);
Maximum of 10 Mb;
Can have audio, but this will increase the file size.
How to compress a PowerPoint presentation
If the PowerPoint presentation's size is over 10 Mb, follow Microsoft's support article here to compress it.
The Powerpoint viewer allows participants to go from slides to slides.
Figures
You can add as many figures as needed using the upload section. The format accepted is:
Image format (jpeg, png, or gif);
Maximum of 100 Mb for each figure;
Click the Edit button to change the title and the description.
Video file
You can upload a video file as well. Make sure to respect those specifications:
.mp4 format;
Maximum of 1 Go;
How long is a 1 Go video?
It depends on the resolution:
720p (HD) is ~5 Mb per minute: 3h20 minutes;
480p (SD) is 2 Mb per minute: 8h20 minutes.
How to record your video
You can use Powerpoint, Zoom, or online tools like Panopto to record a video of your presentation.
How to convert your file to .mp4 format
You can use free online video converters like https://cloudconvert.com to convert from any video format to .mp4
How to compress your video if it is over 1Go
You can use free online video compressing tools like https://www.freeconvert.com/video-compressor to compress your video.