Zonal Statistics giving ERROR 000824: The tool is not licensed

I have a script and when I run the ZonalStatisticsAsTable I get this error:

• File "C:Program Files (x86)ArcGISDesktop10.5ArcPyarcpygeoprocessing_base.py", line 510, in
  return lambda *args: val(gp_fixargs(args, True))
  ExecuteError: Failed to execute. Parameters are not valid.
  ERROR 000824: The tool is not licensed.
  Failed to execute (ZonalStatisticsAsTable).

My code is:

flist = []

    for file in files:
        if os.path.isfile(os.path.join(root,file)) and file.endswith('.shp'):
            flist.append(os.path.join(root,file))```

    arcpy.env.workspace =r"Z:EMSV-057_AOIs_Reshape5_Process1_TaskAModelBuilderPruebas_MVEU_AOICAPAS"
    for z in flist:
       shape=z

       erase=arcpy.Erase_analysis(shape,"C:OSM_coastlineswater_polygons.shp", "Tierra", cluster_tolerance="")

       tZONA=arcpy.gp.ZonalStatisticsAsTable_sa(erase, "FID", raster, "Tabla", "NODATA", "ALL")

import arcpy
from arcpy.sa import *

class LicenseError(Exception):
    pass

try:
    if arcpy.CheckExtension("Spatial") == "Available":
        arcpy.CheckOutExtension("Spatial")

    else:
        # raise a custom exception
        raise LicenseError

      #Your main code here using spatial analyst

except LicenseError:
    print("Spatial Analyst license is unavailable")
except arcpy.ExecuteError:
    print(arcpy.GetMessages(2))