It appears that Apple is discontinuing the Lightning to 3.5mm headphone jack adapter that it released alongside the iPhone 7 ...

If you want to use wired headphones or earbuds on your smartphone, the iFi GO Link Max is an easy way to do it and upgrade the sound coming from your smartphone.

including wired headphones, speakers, car audio systems and aeroplane entertainment. The adaptor first launched in 2016 ...