I succesfully added an EPG to a custom playlist; very nice !
I also have IPTV via xtream code and I use TVmate to view the channels in the different playlists. I try to determine the tvg-id's from some channels. When I use this command: http://url:port/get.php?username=xxxx&password=xxxx&get_live_streams&cat... is see the following output:
{
"num": xxx, "name": "NL | RAKUTEN TOP FILMS", "stream_type": "live", "stream_id": xxx, "stream_icon": "https://xyz/logo1.png", "epg_channel_id": "", "added": "xxx", "is_adult": 0, "category_id": "xxx", "category_ids": [xxx], "custom_sid": null, "tv_archive": 0, "direct_source": "", "tv_archive_duration": 0
},
I don't see the tvg-id's. Am I doing something wrong or am I thinking wrong?
Kind regards,

tvg-id is not a always used.
its up to your provider.
if its anything like the lists i have seen over the years they are a mess.
some channel with tvg-id and some without.
if no tvg-id exists then the name is used to map the channel to epg(xmltv_id value)
NL | RAKUTEN TOP FILMS
in your example above.
Thanks Blackbear