SDF error through drake: Invalid joint type

drake_sdf_wront_joint_type.py

import sys

from pydrake.multibody.parsing import (
    Parser,
)
from pydrake.multibody.plant import (
    MultibodyPlant,
)


def main() -> None:

  plant = MultibodyPlant(time_step=0.01)
  parser = Parser(plant)

  notknownelement = R"""
<sdf version="1.7">
  <model name="robot2">
    <link name="base_link"/>
    <link name="moving_link"/>
    <joint name="slider" type="nontknowntype">
      <parent>base_link</parent>
      <child>moving_link</child>
      <axis>
        <xyz>0 0 1</xyz>
      </axis>
    </joint>
  </model>
</sdf>
""";
  parser.AddModelFromString(notknownelement, 'sdf');

if __name__ == '__main__':
    sys.exit(main())