To send PDF files from Safari to PDF Expert, you can use 2 methods:
Note: If there's no PDF Expert among the available options, scroll the list to the right, tap ... More and select PDF Expert.
The PDF file will be automatically saved and opened in PDF Expert.
Note: You can also open a file from PDF Expert using the URL scheme in Safari.
Type pdfefile:///folder_name/subfolder_name/file_name.pdf to open file_name.pdf stored in a folder or subfolder within PDF Expert.