No Theme header at Blog

I can only speak a little English. I will try to describe the problem. I bought the Theme Edumodo and I am working with Wordpress Version 5.4. No theme Header shows on the Blog. I’m a beginner on Wordpress and i don’t know how to solved the Problem. I have Attached two Screenshots, one is a page with Header and the other the Blog without the header, I hope you understand my english and someone can help me.


Blog Site without Header:
Page Site with Header:

Thanks a lot