Fortunately, it worked with a combination of Safari and an extension called Stay on Mac, iPhone, and iPad.
(The iPhone did not open the settings window, so I wrote the settings directly in the source code and it worked.)
There are three points of concern.
If a post contains a URL, Bluesky does not recognize it as a link and writes it as text.
I want to clear the values regarding Mastodon and Bluesky on my iPad and start over from the beginning, but clearing Safari's cache doesn't make them disappear.
Posts with images attached are prone to errors. This may be due to differences in the upload method.
DeepL translation from Japanese:
Fortunately, it worked with a combination of Safari and an extension called Stay on Mac, iPhone, and iPad. (The iPhone did not open the settings window, so I wrote the settings directly in the source code and it worked.)
There are three points of concern.