Unable to get into the Recovery mode topic

Hi,

I am unable to get into the recovery mode. My Nexus 5 is turned off and not turning on.

Based on the troubleshooting steps mentioned i tried getting into the recovery mode but its not visible. After pressing the Volume Up, Down and Power together i am able to see only the Start Option. Mobile is immdeiately turned off again after this.

Can someone please suggest what needs to be done in this case?.

I need to backup the data as well.

Please do the needful.