Only the original model of express the 3700 won't work with wifi Roku remote, all express models then after can be used with wifi voice remote. If you go into the settings and see an option Remote & devices, it can be paired to wifi remote with tv controls. If you can return the express, the express+ can be have for $24.99 and it comes with wifi voice remote:
Roku Express 4K+ | 4K & HDR Streaming Device | Roku
You can buy voice remotes separately for $19.88:
Amazon.com: Roku Voice Remote (Official) for Roku Players, Roku Audio, and Roku TV : Electronics
