I have assignments with file uploads and Unicheck enabled. I do not have my own unicheck account at this moment.
Can I submit a file to the Unicheck database by using the student view and completing the assignment myself?
It has been a while since I tested the integration (our school went with a different program) but the test student should look just like any other student to unicheck. The test student shows up in grades and that is where the integrated unicheck results were displayed for my classes. Give it a try and see what happens.
I have been able to submit files to another LTI, Smarthinking, as the test student. As long as I did not reset the test student, I had access to the submit file and the responses. The submission from the test student to unicheck should work also.
From what I recall, unicheck should allow whoever is managing your institution's account to issue a sub-account directly to you. If you have more than occasional files to submit directly, you should ask for one.