Printing sprintf without quotes - r

Question

I have some IDs that I want to eventually loop into a larger variable:
playerId <- c(12345, 23456, 34567)
But to first do that, I need to use sprintf to create the necessary lines of code that will run correctly in an API request that looks like something like this when I'm running one at a time:
POST(
'https://api.secure.com/v1/Test',
accept_json(),
content_type_json(),
add_headers(Authorization = VanAPI),
encode = "json",
body=list(playerId = 12345)
)
When I run the above request, it works just fine. But for the purposes of a loop, I want it to look like this:
POST(
'https://api.secure.com/v1/Test',
accept_json(),
content_type_json(),
add_headers(Authorization = ApiKey),
encode = "json",
PlayerIdLines
)
So what I'm doing is creating a series of the necessary line I need for each ID:
PlayerIdLines <- cat(sprintf('body=list(playerId = %s\n)', playerId))
When I first run that line, it produces this output:
> PlayerIdLines <- cat(sprintf('body=list(playerId = %s\n)', playerId))
body=list(targetId = 12345
) body=list(targetId = 23456
) body=list(targetId = 34567
)
But then after that, whenever I try to execute variable PlayerIdLines, all it does is return null:
> PlayerIdLines
NULL
Why is that happening? Why is it being stored as NULL?
EDIT: BASED ON MR FLICK'S ANSWER
I try running the following:
get_data <- function(url) {
POST(
'https://api.secure.com/v1/Test',
accept_json(),
content_type_json(),
add_headers(Authorization = VanAPI),
encode = "json",
body=list(playerId = playerId)
)
}
map_df(playerIds, get_data, .id = 'log') -> CreateDF
But I'm met with the following error:
Error: Argument 1 must be a data frame or a named atomic vector.