I am not able to assign a ticket using REST API to a user as I used to with the following R code. When I checked the documentation, the example shows id (24 characters long generated by JIRA/Atlassian) is required. I am not sure whether the users would share the secret id to use it in the code. Please enlighten me on how to overcome this issue.
library(httr) library(RJSONIO) x <- list(fields = list(project = c(key = "ABC"), summary = "SummaryInfo", description = "Description Text", issuetype = c(name = "Story"), assignee = c(name = "jdoe") )) response <- POST("https://xyz.atlassian.net/rest/api/2/issue/",body = toJSON(x), authenticate("email@example.com","pxxxxxxxxxxxxxxxxxxxxxxx", "basic"), add_headers("Content-Type" = "application/json"), verbose())