Hi, James,
Your instructor will specify the type of entries that are allowed for your submission. It sounds like you are trying to make a submission with a text entry, which you can learn more about here: How do I submit a text entry assignment?
If the images shown in that lesson aren't what you are seeing in your instance of Canvas, try looking at the other information about assignments in our Student Guide.
Let us know if you are able to submit your assignment okay!
Erin
