In order to configure SMS events for FMB640, you need to enable IO elements with which you are going to make events with. In your case, these elements are Axis X (AVL ID: 236), Axis Y (AVL ID: 237), Axis Z (AVL ID: 238). In this case, the operand is "On Delta Change" and the "High Level" is 10. That means that the event will be generated when any of the axis changes by 10 mG.
More information about operands: https://wiki.teltonika-gps.com/view/FMB640_I/O_settings
More information about IO elements: https://wiki.teltonika-gps.com/view/FMB640_AVL_ID#Permanent_I.2FO_elements
In "SMS Events" window in "SMS Events AVL ID" you should write your IO element/elements AVL ID which you want to make SMS event/events. In "SMS Events Number" you should select number, which you typed in "SMS \ Call Settings" tab, under the "GSM Predefined numbers" list.
In "SMS Event Text" you should write text which you will get after generating event.
Hope that helps.