Welcome to the Roku Community! Thanks for the inquiry.
The Remote Finder feature is currently not available to Roku Streambar, this feature is available to our Roku Ultra (4800R). In addition, our latest Roku Voice Remote Pro (purchased separately) is compatible with Roku Streambar (9102x) and has a lost remote finder feature.
For more information about Roku remote finder feature, visit our Support page here: How do I find my Roku® remote using remote finder?
Let me know if you have any other questions, and have a good day!