How you export patterns on your iPad depends on the iOS version you have. Here is a handy overview.
When exporting your pattern, you should see the following dialog box. Choose Download.
Safari will export your pattern to the downloads folder in your "My Files" app. Under the ⬇button you can find your recent downloads.
<aside> ❗ When exporting a pattern in Chrome on iOS 13, the browser will navigate away from the app and display the pattern. You can save the pattern by press and hold for 2 second, then choose "Save image" from the option list.
When exporting your pattern, you should see the following dialog box. Choose Allow.
This will open a new page with the exported image. It is only being displayed, not yet saved.
Tap the ⬆️button (1), then choose Save Image (2) from the options. This will save your pattern to the camera roll.
On iOS 11, the ⬆️Button may or may not contain an option to save your image. If not, press for two seconds on the image itself. An option should appear to save your image.