Do you want to turn off ring on your cordless phone? If yes, then do this:
Press [MENU] [#]   .
Press the [▲] or the [▼] button to raise, lower or turn off the ringer volume.
But if you want to tun off it completely then press the 'phone/power off' button (the button with a symbol of a red phone with a line through it on the right hand side!) for about 2 seconds - to turn it on you have to press the same button for 1 second.
Check more details in Panasonic KXTGD532 Manual- https://guideusermanual.com/product-name-kxtgd532-manual&po=639506&lang=English