Hello @Vinay_Kumar , As far as I know, there isn’t a “complete course” button in Open edX platform – “completion” of a course involves completing all of the modules in a course.
Here’s some details about how different types of modules get marked completed: Learners having trouble with completion indicators - #2 by xitij2000
But if you think adding a “complete course” button would help with learner confusion, you could submit a PR to add it, or submit a feature request and find a provider to implement it for you.