It Has to Be Named .jpg
The check reads the filename, not the file.
Uzbekistan's e-visa portal accepts .jpg files only, and the check is literal: the uploader splits the filename and compares the extension as text. A perfectly valid JPEG saved as photo.jpeg is refused, because the string after the dot is not exactly "jpg".
That is worth knowing because plenty of software writes .jpeg by default. If your file is rejected and you cannot see anything wrong with the photo, look at its name before you retake it.
PNG, HEIC and PDF are refused regardless of quality — and HEIC is what modern iPhones produce by default, which is the other common stumbling block.
