It was a cheap shot, I know...
I access SQL server regularly, the connection I use is as follows:
library(odbc)
con <- dbConnect(odbc(), Driver = "ODBC Driver 17 for SQL Server",
Server = "my-server", Database = "my-database", UID = "my-login",
PWD = "my-password", Port = 1433)
MS SQL Server is not my preferred RDBS for working from R (Postgres is much more fun) but it works; and the benefits of an MS ecosystem (Power BI and stuff) are unquestionable, especially in a corporate environment.