Plotting proportional symbol map of horse mackerel species using R

library(sf)
library(rgdal)
library(cartography)
hm_SHP <- st_read(file.choose())

Reading layer Oman -coastline' from data source /Users/salmanmaf/Documents/OMAN map_shapefiles/OTrIs/Oman
-coastline.shp’ using driver `ESRI Shapefile’ Simple feature collection with 2279 features and 2 fields geometry type: POLYGON
dimension: XY bbox: xmin: 46.2 ymin: 14.5 xmax: 65.6
ymax: 29.1 CRS: NA

hm_sp <- read.csv(file.choose())

plot(st_geometry(hm_SHP))

plot(hm_SHP) 

# Total length plot on proportional symbols
propSymbolsLayer(x = hm_SHP, var = "TL",
                  symbols = "circle", col =  "white",
                  legend.pos = "right", border = "grey",
                  legend.title.txt = "TL",
                  legend.style = "c")

Error in abs(x[[var]]) : non-numeric argument to mathematical function

I got the above error but what is the problem?