Your going to need a Wifi remote, and pair it to your stick. You can purchase it from roku in the link I provided, or go to your local Walmart or Best buy and get the rc-al7:
https://www.walmart.com/ip/Roku-Voice-Remote-NEW/506651807
Is the stick purple? Then its the 3500 and they don't have replacement that works with that model. You might turn to ebay for a used remote?
The first remote you purchased does it have pairing button in the battery compartment?
So if your roku stick is 3600, 3800, or 3810 stick + then the following remote will work, first listed on this page;
https://www.roku.com/products/accessories/player
Your going to need a Wifi remote, and pair it to your stick. You can purchase it from roku in the link I provided, or go to your local Walmart or Best buy and get the rc-al7:
https://www.walmart.com/ip/Roku-Voice-Remote-NEW/506651807