The shortcut should be Ctrl+Alt+E. But it currently doesn't work for me.
I tried to customize with another sequence (in case the built in sequence was already taken on my machine) but that didn't work either.
Looking at the customize shortcuts window (via Tools/Modify) I see that the scope of the shortcut is R.
The 'beginning to current' shortcut is scoped to Editor (which makes more sense).
What am I missing?
Just in case it matters, I'm running Version 1.4.1103.
R version 4.0.2 (2020-06-22)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18363)