1996 Toyota camery lx cassette adapter?

So I bought a Cassette adapter for my 96 toyota camery lx because the radio is trash now a days. For some reason the tape deck keeps spitting the adapter out. It will play for 2 seconds, on and off and then spit it out.
Does anyone know why it does this and can provide a solution or better means of playing music from my iPhone

You can buy an adapter you can plug in to your cigarette light plug hole. Or an fm transmitter