Maybe this workaround, uploading to YouTube, is useful for someone. YouTube creates subtitles for the original language of the video and translates, but the translation is only from English to other languages, the opposite is apparently not available (step 9-10).
1. Upload your video to youtube:
2. In "Advanced settings" tab - "Video language" define the original (if you want to translate, the original may have to be english):
3. Enter your channel:
4. Enter YouTube studio:
5. To the left side, click on Videos, and select your video.
6. Having your video opened (important - step 5), click on Transcriptions on the left side, and on the right side click ADD LANGUAGE blue button:
7. to the right side click ADD, blue square with arrow:
8. To the right side click on "Create New subtitles or CC":
9 and 10. click up left in "Autotranslate" and then to the right "save changes" (important):
11. click in the language of interest, translated in step 10; click in Actions, now you can choose the desired format. for ex. .srt (.srt is not available in step 9)
12. There might be significant overlap among sentences. I use Gaupol (link to install) to reduce that: (Tools menu - Adjust Durations)
13. Now, use MKVToolNix (has GUI) or HandBrake to add subtitles to video.
Example: (command line version)
sudo apt-get install mkvtoolnix mkvtoolnix-gui
mkvmerge -o outputfile.mkv inputfile.mp4 subtitle.srt