Using iCloud creates a problem for syncing Rocketbook files directly into your Obsidian folder. To solve this issue, you need to use automation to move the uploads. Here’s how:
First, set up a new destination in the Rocketbook app on your iOS device. Open Rocketbook, tap Destinations, and change it to iCloud. Create a new folder for syncing with your iCloud account.
Next, create an automation using the Shortcuts app. Tap Automation, select App > Rocketbook, and disable Is Open. Run Immediately and tap New Blank Automation. Search for Get Contents of Folder and select your Rocketbook folder. Then, search for Move File and choose your Obsidian vault folder instead.
This setup will automatically sync Rocketbook files into your Obsidian vault as soon as you close the Rocketbook app. It’s a convenient solution that saves paper and reduces waste.
Source: https://www.xda-developers.com/combined-rocketbook-and-obsidian-to-automate-note-taking