Using the Jon Maddox container, I can see the Season and Episode in the data it pulls from the Pluto API (it's cached in the container /usr/src/app/cache.json)
"_id": "66d12f8de0873100133e3749",
"start": "2024-09-20T19:12:00.000Z",
"stop": "2024-09-20T20:07:00.000Z",
"title": "Little House on the Prairie",
"episode": {
"_id": "6567c9da2f9f5b001351ef75",
"number": 4,
"season": 2,
"description": "The Green-Stockings of Sleepy Eye challenge the men of Walnut Grove to a baseball game.",
"duration": 3300000,
"originalContentDuration": 3300000,
"genre": "Classics",
"subGenre": "Classic Dramas",
"distributeAs": {
"AVOD": false
},
"clip": {
"originalReleaseDate": "1975-10-01T00:00:00.000Z"
},
"rating": "TV-G",
"name": "The Big Inning",
"slug": "the-big-inning-live-epg-2-4-ptv1",
"poster": {
"path": "https://images.pluto.tv/episodes/6567c9da2f9f5b001351ef75/poster.jpg?fill=blur&fit=fill&fm=jpg&h=1000&q=75&w=694"
},
"firstAired": "1975-10-01T00:00:00.000Z",
"thumbnail": {
"path": "https://images.pluto.tv/episodes/6567c9da2f9f5b001351ef75/thumbnail.jpg?fill=blur&fit=fill&fm=jpg&h=440&q=75&w=440"
},
"liveBroadcast": true,
"featuredImage": {
"path": "https://images.pluto.tv/episodes/6567c9da2f9f5b001351ef75/featuredImage.jpg?fill=blur&fit=fill&fm=jpg&h=900&q=75&w=1600"
},
"series": {
"_id": "65666a8a20854800140c4820",
"name": "Little House on the Prairie",
"slug": "little-house-on-the-prairie-live-epg",
"type": "live",

but it doesn't pass it in the XMLTV output.
<programme start="20240920121200 -0700" stop="20240920130700 -0700" channel="little-house-on-the-prairie">
<title lang="en">Little House on the Prairie</title>
<icon src="https://images.pluto.tv/series/65666a8a20854800140c4820/tile.jpg?fill=blur&fit=fill&fm=jpg&h=900&q=75&w=900"/>
<date>19750930</date>
<category lang="en">Series</category>
<series-id system="pluto">65666a8a20854800140c4820</series-id>
<desc lang="en">The Green-Stockings of Sleepy Eye challenge the men of Walnut Grove to a baseball game.</desc>
<category lang="en">Classics</category>
<category lang="en">Classic Dramas</category>
<live/>
<episode-num system="original-air-date">20240920121200 -0700</episode-num>
<category lang="en">Drama</category>
<category lang="en">Drama</category>
<category lang="en">Drama</category>
<sub-title lang="en">The Big Inning</sub-title>
</programme>
