Hi, and welcome!
Please see the FAQ: What's a reproducible example (`reprex`) and how do I do one? Using a reprex, complete with representative data will attract quicker and more answers. (However, this question doesn't require one.)
To create an Rds file in the current working directory
save(an_object, file = "an_object.Rds")
and to read it back in
load("an_object.Rds")