Problems with getting all panel info for A19 bulb

Hello! I have some problems with getting all panel info for A19 bulb. I tried to use this syntax:
curl -X GET "http://192.168.1.20:16021/api/v1/AUTH_KEY/"

BUT I've received 500 code.

Please, tell me current syntax.
firmware: 3.0.3
hardware: 1.1.0
model: NL75K1