You are not able to cancel your shift using Quinyx. If you are sick and are unable to work during our scheduled shift, create an absence. You can do this in Quinyx by:
Go to the leave applications tab and click on “+” to add a new request
Define reason type (vacation and sick leave request - not yet approved), dates and add a comment if wished
Click save, and you will be informed once a decision has been made
Check the article here to know how to request an absence: How do I request an Absence?