There are two ways to edit a draft in Canary on iOS:
1. Edit Minimized Drafts:
- Tap on ‘Compose’.
- Select ‘Edit: <draft>’.

Note: Minimized drafts will be deleted if you force quit Canary.
2. Edit Saved Drafts:
- Open the ‘Drafts’ folder.
- Tap on the message you want to edit.
- Tap on the ‘Compose’ icon or the ‘Reply’ button at the lower right part of the screen.
