How do I create a world map with a heat map on top of it-CodePudding

I have been trying to create a world map in R with a heat map overlaid on top of it. I have a dataframe called mydata in which there are 2 columns, the first column is country_code_author1 with ISO3 country codes, and the second column called "n" with the count of how many publications each country has. I attached the code I am using below, but it is only producing a heat patch on the United States when I run it. I attached a picture of my data frame below.

library(maps)
library(ggplot2)

mydata <- df_country_count_auth1

world_map <- map_data("world")
world_map <- subset(world_map, region != "Antarctica")

ggplot(mydata)  
  geom_map(
    dat = world_map, map = world_map, aes(map_id = region),
    fill = "white", color = "#7f7f7f", size = 0.25
  )  
  geom_map(map = world_map, aes(map_id = country_code_author1, fill = n), size = 0.25)  
  scale_fill_gradient(low = "#fff7bc", high = "#cc4c02", name = "Worldwide Publications")  
  expand_limits(x = world_map$long, y = world_map$lat)

Code/Structure for a mini version of my dataframe

myData <-
  structure(
    list(
      country_code_author1 = c(
        "AGO",
        "AIA",
        "ALB",
        "ARE",
        "ARG",
        "ARM",
        "ATG",
        "AUS",
        "AUT",
        "AZE"
      ),
      n = c(3L, 1L,
            11L, 3L, 38L, 1L, 4L, 240L, 98L, 23L)
    ),
    row.names = c(NA,-10L),
    groups = structure(
      list(
        country_code_author1 = c(
          "AGO",
          "AIA",
          "ALB",
          "ARE",
          "ARG",
          "ARM",
          "ATG",
          "AUS",
          "AUT",
          "AZE"
        ),
        .rows = structure(
          list(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L),
          ptype = integer(0),
          class = c("vctrs_list_of",
                    "vctrs_vctr", "list")
        )
      ),
      row.names = c(NA,-10L),
      class = c("tbl_df",
                "tbl", "data.frame"),
      .drop = TRUE
    ),
    class = c("grouped_df",
              "tbl_df", "tbl", "data.frame")
  )