Choices are All, Current Page, Selected Pages, Pages, All Pages, Odd Pages Only, Even Pages Only. Enter language, accuracy, output type/quality Specify primary language.
Immediately available are English, French, German, Spanish. Click More Languages to visit the web for others. Specify accuracy: Low (fastest), Medium, High (slowest). Select Create New Searchable PDF or Preserve Original Content and Add Text Layer. If choosing the former, you may select a Quality (300 is usually fine for a typical PDF) and/or Auto Deskew (straighten). Save the OCR'ed document Do a File>Save or File>Save As or another Save choice on the File menu to save the PDF with the text from OCR (but Save Optimized Copy is not available in the Free Version).