This is the key

IOS users who download files will find that it opens in a separate tab on the Safari browser. At the top right on the browser the user will see

Touch or click the left-hand icon, the box with the arrow at the top, and in the following dialog box select options

And in the following part select PDF.

You can then select where you want your PDF to go.

If you select “save to Files”

you will see something like

What you see may differ from the above image depending on what apps you have installed, for example if you have Dropbox on your device you will also see a folder for that here. If you don’t have Excel, Word or GarageBand then you won’t see those folders. Click Save at the top left of the dialog box.

To find the file on your device find Apples’ Files App and open it. If you saved it to a Cloud storage folder navigate to there or if you saved it to, for example Downloads, go to “On My iPad” and select the folder where you saved it.