IEC-60320 C7 (Figure are not rated for in wall usage. If you have an outlet below the location of the speakers, you can buy a short cord and one of these per speaker:
https://www.sonos.com/en-us/shop/sanus-in-wall-power-kit-for-all-in-one-speakers
What I did when installing Sonos Ones in my breakfast nook was to have an electrician install plugs at ceiling height, so I could run short power cords to each. Satisfied all local codes, and kept the wires to a minimum. After a week of them going in, I didn’t ‘see’ them anymore, and just enjoyed nice music.
Had I not already had the Ones, I might have gone with the Sonance and Sonos Amp option, instead.