Resetting the Roku, which is what you did BEFORE changing your Wifi Name and Password on your router/modem back to what it was before all this, is the reason you can't set up the wifi connection for your Roku with the Roku App. Before you reset the Roku, it had your old Wifi name and Password saved and would have automatically connected to your router/modem (Wifi) after you changed it back to the old Wifi Name and Password. So, I guess you'll have to wait on getting a remote for it.
Edit: I was assuming that was you on Reddit. If you can remember your old Wifi Name and Password you had for your previous internet/router/modem before, change the Wifi name and Password in new your router (or Router/Modem Combo Unit) settings to what it was before in the old router/modem. Sorry. (As long as you didn't factory reset your Roku Stick, it will have your Old Wifi Name and Password in memory and will automatically connect.)
You may have to scroll down and change the site from Canada to United States. Then scroll down and tap on Products > Accessories. Then scroll down on the page and tap on Streaming Stick Accessories and you'll see the remote and it says it's compatible with the 3600 - it's a voice remote. I think you can order it through the US site. You could always contact Roku Support by phone or their website to order the remote too. Also, you can contact RokuSupport on Twitter. They are @RokuSupport on Twitter.
If you change your wireless SSID and password to the same you used on your old Internet, you should be able to get the Roku connected again. As long as you haven't reset the Roku it remembers and will connect to the last used wireless connection.
Dan Roku Stick (3600), Ultra (4640), Ultra (4670), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.