Running a PlayStation 4 emulator natively on an Android device with only 1GB of RAM is not possible with current technology . Legitimate PS4 emulators like

: Some newer Android versions allow you to use internal storage as "Virtual RAM," though this is rare on older 1GB devices. : Advanced users might root their device to install a minimalist Custom ROM

When searching for this keyword, you will see links like:

While you cannot "emulate" a PS4 locally on a low-spec phone, there are alternative ways to experience PS4 titles: