GET httr - API KEY

Hello Guys, could someone help me, please?

I'm trying to learn abouts websites APIs anda httr package, but i always get an invalid API KEY error, i'm using the keys i received, am i using the GET command wrong?

endpoint <- "https://ipage_cep.p.rapidapi.com/ws/cep/v1/application/views/cep/?cep=50870050&key=MY_API_KEY"
res_api <- GET(url = endpoint)
content_text <- rawToChar(res_api$content)

Or
res_api <- GET(
url = endpoint,
query = list(
apikey= key_api,
details = "true"
)
)
content_text <- rawToChar(res_api$content)