How to add an external shapefile using cartopy in geemap?

Question

I am trying to add a shapefile over a satellite image using cartogee in geemap. I got successful in plotting the satellite imagery but got error while adding the shapefile. The script I used is  

# Set range of map, stipulate zoom level
ax.set_extent([90.1705247321613115,26.0299380202123096 , 90.1918066009087056,26.0460906028715726], crs=ccrs.Geodetic())

fig = plt.figure(figsize=(10,7))

vis = {
    "bands":["VV","VV","VV"],
    "min":-25,
    "max":0,
   #"palette":['aqua', 'black']
}

# use cartoee to get a map
ax = cartoee.get_map(Sentinel_1,vis_params=vis,region=zoom_region)

# add a colorbar to the map using the visualization params we passed to the map
cartoee.add_colorbar(ax, vis, loc="right",label="Backscatter",orientation="vertical")

# add gridlines to the map at a specified interval
cartoee.add_gridlines(ax,interval=[0.005,0.005],linestyle=":")
filename = r'E:/Final shapefiles.shp'
shape_feature = ShapelyFeature(Reader(filename).geometries(), ccrs.epsg(32646), 
                               linewidth = 1, facecolor = (1, 1, 1, 0), 
                               edgecolor = (0.5, 0.5, 0.5, 1))
ax=add_feature(shape_feature)
plt.show()

And the error is

    NameError                                 Traceback (most recent call last)
<ipython-input-125-7e5d43a82605> in <module>
     23                                linewidth = 1, facecolor = (1, 1, 1, 0),
     24                                edgecolor = (0.5, 0.5, 0.5, 1))
---> 25 ax=add_feature(shape_feature)
     26 plt.show()

NameError: name 'add_feature' is not defined

But I get the image output as

Output is without the shapefile due to error