The key can be either specified in various ways see the Details section.
check_key(key = NULL)
if found the character string of the key,
There are several ways to provide your API key.
The best way to know about them is to refer to the vignette about
"Setting Up Your API key" accessible with the following command:
vignette("setting_up_api_key", package = "rromeo").
You can also use
rr_auth that will use the provided key to store it as
an environmental variable.