how to add ui select field with ajax call option magento 2 admin add/edit form

How to add field in the add / edit for for ui select with search option. i have added in the add form but it is not working.

[![enter image description here][1]][1]
[![enter image description here][2]][2]

[![enter image description here][3]][3]

Can you please let me know that how to use ui select field in the form magenteo 2.
[1]: https://i.stack.imgur.com/CbXlR.png
[2]: https://i.stack.imgur.com/hwlJa.png
[3]: https://i.stack.imgur.com/3d5cs.png