no option to save file as photoshop pdf

Hi, i just got a new mac desktop and installed the newest photoshop. No i dont have the option to save a file as a photoshop pdf anymore. I think its because the files are to big? But i didnt have this issue before. I could save every document as a photoshop pdf file. I allready set the settings to an older version but that doesnt change anything. I use photoshop to make my files smaller, they have to many pixels. Does anybody have a tip to make the pixels less without loosing quality or how to fix the problem that i have?  Sory for my english. Im dutch. Thanks