Please go to Davinci Resolve preferences and check if you can see it in video plugins
If it is disabled - enable, save and restart.
If there is still a problem. then:
macOS
- Close DaVinci Resolve
- Open OpenFX plugin cache file location
- Open a Finder window
- Select Go > Go to Folder...
- Type or paste in:
~/Library/Application Support/Blackmagic Design/DaVinci Resolve - Delete the OFXPluginCacheV2.xml file at this location
- Restart Davinci
Windows
- Close DaVinci Resolve
- Open OpenFX plugin cache file location
- Open a File Explorer window
- Go to C:\ProgramData\Blackmagic Design\Davinci Resolve\Support\
- Delete the OFXPluginCache.xml file at this location
- Restart Davinci