An empty guide is one of the more common minor IPTV annoyances, and usually has a simple fix.
Wait a few minutes
EPG data can take longer to populate than the channel list itself, especially right after first login.
Refresh the playlist
Most apps have a refresh or reload option in settings that re-fetches both the channel list and EPG data.
Check for a separate EPG URL field
Some players (particularly M3U-based ones) need a separate EPG URL entered alongside the playlist link.
Confirm you’re viewing live channels, not VOD
The EPG only applies to live TV; the movies and series section works differently.