You "should" be able to use another roku device's remote if you pair it to the TV if the remote has the pairing button located in the battery compartment of the remote.
Turn TV on manually with TV power button. Press pairing button on remote until green button flashes. Wait a few seconds and you should hear some audible beep/blurp from the TV. **If no green light, you need to replace batteries in remote.
Otherwise, Walmart and Best Buy are now selling the enhanced remotes for about $20 in their stores if you are shooting for immediate fix.
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
Insignia RokuTV, Ultra 4660x, Premiere+ 3921, Express 4k+ 3941