The example commands below work from Vera for me.
All the other Kodi Leia v18.X API commands can be seen here.
Update Video Library
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"VideoLibrary.Scan"}\'')
Pause / Play
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc": "2.0", "method": "Player.PlayPause", "params": { "playerid": 0 }, "id": 1}\'')
Navigation
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.Up"}\'')
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.Down"}\'')
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.Left"}\'')
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.Right"}\'')
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.Select"}\'')
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.Back"}\'')
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.Info"}\'')
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.Home"}\'')
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.ContextMenu"}\'')
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.ShowOSD"}\'')
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.ShowPlayerProcessInfo"}\'')
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Input.ShowCodec"}\'')
Launch Kodi Add-on
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","id":1,"method":"Addons.ExecuteAddon","params":{"addonid":"script.frontgardencam"},"id":"1"}\'')
Disable Kodi Add-on
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","method":"Addons.SetAddonEnabled","params":{"addonid":"script.kodi.hue.ambilight","enabled":false},"id":1}\'')
Enable Kodi Add-on
os.execute('curl -X POST -H "content-type:application/json" http://username:password@192.168.1.5:8080/jsonrpc -d \'{"jsonrpc":"2.0","method":"Addons.SetAddonEnabled","params":{"addonid":"script.kodi.hue.ambilight","enabled":true},"id":1}\'')