Add Xray issue types to your schemes
Your team will need to create all the Xray issues inside the project you are enabling to use Xray.
In order for this to happen, you need to make Xray issue Types available in your "Issue Type Schemes" and in your "Issue type Screen Schemes".
XRAY Issue Types available
Your team does not to use all Issue Types at their project. If you want to go for a simple approach you might only use - Test, Test Plan & Test Execution.