Removing toggle buttons from left/right sidebar

Does anyone know how I can remove the toggle button for the left sidebar in shinydashboard/ shinydashboardPlus?

I found a suggestion at:
https://github.com/coreui/coreui-angular/issues/4#
but I can't seem to be able to implement it.

I tried following without any luck:
tags$head (
HTML ( "<app-header [sidebarToggler]=false [asideMenuToggler]=false>")
)