1. Prepare a desired frequency on the radio and transmitter (for example: 88.1MHz)
2. Start the music on your phone
3. Done
The transmitter sits relatively firmly on the smartphone.
I'm not entirely convinced of the sound quality, but find that the FM transmitter for the competitive price already transmits OK.
It is not overwhelming but not bad - Because Amazon 3 stars = not bad / mean Alright, I give 3 stars!