What skills, experience, and/or responsibilities are expected for moving from a mid-level engineer to senior level?

I have been working in IT for 8 years, with 5 years specifically in Networking. I started at my current company 2 years ago as a mid-level engineer. My manager has previously talked about the way everyone on my team can "move up" in our careers, saying I would be on the same level of where our currently only sr. engineer is. Last month during pay raise discussions, they said that 2021 is the year for new job titles and re-evaluating compensation, implying that this is my chance.

I'm planning to bust my ass and deserve that promotion, but I could use some direction and guidance. I will for sure ask the sr engineer I work with, but I would really appreciate some tips from this community.