Leaflet only works with e_scatter and e_effect_scatter.

Scatter

url <- paste0("https://ecomfe.github.io/echarts-examples/",
              "public/data-gl/asset/data/population.json")
data <- jsonlite::fromJSON(url)
data <- as.data.frame(data)
names(data) <- c("lon", "lat", "value")
data$value <- log(data$value)

data %>% 
  e_charts(lon) %>% 
  e_leaflet() %>%
  e_leaflet_tile() %>%  
  e_scatter(lat, size = value, coord.system = "leaflet")