Adding a value in a chart which is not present.

Very difficult to provide specifics here. Please see this post regarding How to Get Your Question Answered Quickly: https://community.powerbi.com/t5/Community-Blog/How-to-Get-Your-Question-Answered-Quickly/ba-p/38490

But, in general you can solve these kinds of problems by creating your measure with an IF statement that if it is going to return BLANK, (ISBLANK) return 0 instead.