In a AWS Lambda custom runtime of R programming, how would you save a PDF to S3 using the aws.s3 R library?

Question

In an AWS Lambda with a custom runtime of R 4.2.0, after creating several PDFs using

ggplot2::ggsave(plot=x, filename=paste0('/tmp/test_',[i],'.pdf)

saving them in the AWS Lambda container '/tmp' directory, then combining them with pdftools::pdf_combine(input=listoffiles, output='pdfname.pdf')

How would I get a handle on the 'pdfname.pdf' (object?) to save to S3 using the R aws.s3 library (possibly aws.s3::s3_save() or aws.s3::s3write_using()), please?

Or are there other libraries that I can use to save a PDF to S3 in R programming?