As of SVN #8278, the apple2/apple2p/apple2e drivers support the cassette interface (read only for now). I haven't had much luck with Integer BASIC tapes, but Applesoft stuff like Color Demosoft or the Applesoft version of Little Brick Out loads and runs fine.
For the II Plus and IIe, turn off full keyboard, press F3 (reset) to drop into BASIC, type LOAD and press Enter, then start the tape playing via the Tab menu or WinUI.