On iPhone, Obsidian can only open vaults in the Obsidian folder in “On my iPhone” and the Obsidian folder in iCloud.
This post from a year ago suggests a companion app may be needed:
On iPhone, Obsidian can only open vaults in the Obsidian folder in “On my iPhone” and the Obsidian folder in iCloud.
This post from a year ago suggests a companion app may be needed: