A programme that needs adding to a series

I have recently seen an episode on Television (Sky Arts channel).

but looking at the credits and similar programmes with cast too (even though it is not complete), it should belong in the series,

https://www.imdb.com/title/tt9421686

I cannot find a way to add this to the series, so is there a way for someone to be able to rectify this please.

Many Thanks

Britrick_c21