This depends entirely on org culture. I've worked at places where I had to go thru an absolute gauntlet of "prep" meetings to hone my talking points for talking with someone several skip levels above my manager.
And, I've worked in places where you are free to send a DM to the C-Suite if you feel like it's necessary to get your work done. No pre-approval required.
And, I've worked in places where you are free to send a DM to the C-Suite if you feel like it's necessary to get your work done. No pre-approval required.