Not sure of a compatible manufacturer you could try if not listed, short of trying them all. Perhaps someone can offer some info to save you some time (@Tivoburkee). I am assuming here you are trying to get your Roku remote to work with this TV.
I did see some info that two remotes are (or at least were) usually shipped with the older Cosmos units due to how the Android OS was actually integrated into the TV. (an attached Android box inside the TV). If still the case, may turn out that you cannot use the Roku remote with your TV to control power and volume, but do not want to speak prematurely until others weigh in.
Roku Community Streaming Expert Just another Roku user... I am not a Roku employee. Insignia RokuTV, Ultra 4660, Premiere+ 3921, Express 4k+ 3941, Streambar 9102
According to Evervue themselves, Cosmos is a brand name used on outdoor TV sets.
I’m into videotapes and old electronics stuff, including extenders, converters and analog 4:3 TV sets (which are obsolete these days), and Miss Bianca is my favorite character in Disney’s The Rescuers (1977) and its sequel, The Rescuers Down Under (1990). I am not a Roku employee, only a user like you. ~ Jordan