Print to PDF

Let’s say there is a document or file on my iPad screen with Print button. I want to print the file or document to PDF, and not as a physical document by way of a printer. And let’s assume, the share option is not coming up. In Windows 10, there is the “Microsoft Print to PDF” and I will just choose “Microsoft Print to PDF” and it will generate a PDF file for me. What about in the iPad? How can I readily “print” to PDF what I have on my screen or if there is Print button, tapping the print button should readily enable me to print to PDF?

Thank you in advance.