Allowing a show to only obtain data from a single source

[Drake97]

Hello everyone,

I have a small problem, it turns out that there is a docuseries that only exists in my country and it was not listed in any database page (tvdb, Imdb, etc) therefore the metadata was not obtained.
What I did was to manually create the docu in thetvdb, adding all the details, pictures and so on, quite an arduous job haha, however, Jellyfin takes the posters and texts, but still brings me a similar show from Turkey and thus fills in the backgrounds and thumbnails of the chapters and it's stressful.
Is there any way to force Jellyfin not to do this and just get the pictures of the show I created ? Or make the thumbnails of the chapters to be pictures of the chapter itself and not the Turkish series.

Thanks in advance