Shiny group_by with one reactive value and one ordinary column name

please is there a way I can make this work

reactive({
.....%>%
group_by(input$col1, col2)%>%
summarise()....
})

I'm guessing you need the !! or "bang bang" operator to interpret input$col1 as a variable in the dataframe being grouped.

reactive({
.....%>%
group_by(!!input$col1, col2)%>%
summarise()....