You need to buy Part # RS-DM0075, its only about $10. The part include water spray and shot of steam buttons, washer etc. The spring could be broken, but you will need a Torx T20 security bit (has a hole in the bit) and a Trox T10 to take apart the DM880.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix steam irons.