Try the following way:
<exportButton name="export_button" class="SR\OrderRefundReason\Ui\Component\ExportButton"/>
Now create following class:
<item name="js_config" xsi:type="array">
<item name="provider" xsi:type="string">[...
I am placing this answer, to allow someone having same issue get help.
Investigating how magento core solves this issue (thinking I am missing something in my UI Component setup), I found this line of code: