obs to wowza not working - empty playlist.m3u8 in the client side

Wowza Streaming Engine
1

In OBS I entered:

URL: rtmp://[server ip]:1935/[app name]
Stream key: [stream file]

No authorization (I disabled it in wowza)

I can see the playlist.m3u8 but it’s empty.
In wowza monitor I can see the rtmp stream.

Why it’s not working?