How to set form accessibility

I have this form enabled and the accessibility option is enabled, but it doesn't pass siteimprov's accessibility checker. It totally fails!!!! What's up with this????

https://form.jotform.com/uofsc_cmcis/MIA-Application

The images don't have alt text or anything like that. How do I mark them as decorative?

May we know the issue with your form accessibility?

I have checked your form and are you referring to your logo image reference link?

Looking forward for your response.