Using Stadia Maps (formerly Stamen Maps) tiles requires setting up a free API key and registering it in your R session, this helper function helps you set up your session accordingly.
Details
To get an API key, you must sign up at https://client.stadiamaps.com/signup/Stadia Maps sign up.
See also
Other map functions:
add_map_e61(),
crop_aus_coord(),
theme_e61_spatial()