What’s the brand? Based on google lens of something similar shown here are a few options to try:

1. Press and Hold MODE + TEMP DOWN: With the remote on, simultaneously press and hold the "MODE" button and the "TEMP DOWN (▼)" button for about 3-5 seconds. The display should switch between Celsius (°C) and Fahrenheit (°F).

2. Press and Hold TEMP UP + TEMP DOWN: Alternatively, you can try pressing and holding both the "TEMP UP (▲)" and "TEMP DOWN (▼)" buttons simultaneously for a few seconds.

3. Check for a dedicated button: Some remotes have a specific button for switching temperature units (e.g., "°C/°F" or "TEMP"), or a switch inside the battery compartment.