If your question relates to Letterboxd, you need to direct it at Letterboxd, not TMDb. TMDb can't upload backdrops to Letterboxd.

Backdrops are not imported automatically on Letterboxd. You need to submit a backdrop request via the report flag on the film's page on Letterboxd if you want to ask them to upload a backdrop.

I remember reading somewhere that Letterboxd only imports some information in English.
So maybe it doesn't import backdrops in Spanish.
Only in English or without a language set.

Importing from only the English translation relates to textual elements (such as synopses/overviews, taglines) for Letterboxd.

Backdrops don't get imported automatically at all, regardless of language.

I have uploaded it correctly, but it still does not appear in Letterboxd, what should I do?

In letterboxd there is no option that I can see to correct that.

As Ruby already pointed out, you need to request the backdrop at Letterboxd, TMDB can't help you with that. Click on the flag symbol on the Letterboxd page for the movie and make an "Image Request" (not possible on mobile as far as I know)

Well, Letterboxd says this:

_"*Can I upload my own poster or backdrop image to Letterboxd? * No (with one exception: HQ accounts can upload a backdrop profile image).

The poster and backdrop images offered on Letterboxd are sourced from TMDB (and Posteritati for additional posters), and there is no option to upload your own image directly to our platform. TMDB accepts user submissions, but please follow the published guidelines when uploading images, as abuse of TMDB’s rules may lead to customization features being suspended on your Letterboxd account. Infringing content includes, but is not limited to, images containing: spoilers, inappropriate nudity, graphic violence, fan art and memes. TMDB submissions can take up to seven hours to appear on Letterboxd due to caching at their end."

I am absolutely sure that I have correctly complied with the standards/rules for the correct export of backdrop images.

In the last part it says: “TMDB submissions can take up to seven hours to appear on Letterboxd due to caching at their end.” _

I am absolutely sure that I have correctly complied with the standards/rules for the correct export of backdrop images.

In the last part it says: “”

but it has been 3 days since I uploaded all the images and they are still not applied, or I have not been able to see them in the application or on the Letterboxd website. Anyway, I have done what I have been told in this discussion. I will wait for the answer.

Thank you very much, any feedback you have, (or if I have it myself after the answer, if Letterboxd gives it to me), then I will share it with you.

How many times do you need to be told to stop contacting TMDB to upload backdrops to Letterboxd? They cannot do it.

You've already been explained how to submit a request to Letterboxd to add a backdrop. If you don't understand the English language, please use an automatic translator, like Google Translate: https://translate.google.com/

Go back and read the last thing I wrote, since I have said what Letterboxd says regarding my problem. Don't be undesirable, you seem to have left your education locked up at home.

If you don't want to help me or answer, better get yourself, no need for that bad answer. Have a happy rest of the evening.

You have been given the correct answer, and still you keep reopening a thread and bothering the two mods as well as myself who tried to help you, with your notifications. Please have some respect and read what people have told you already. I'm unfollowing this discussion.