NavSat_Transform in Robot-Localization package does not publish anything to /odometry/gps

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I am using robot localization package to fused data from GPS, IMU & odom using NavSat Transform of Robot-localization, but it's not publishing anything

Here is the launch file I used

<launch>
 <node pkg="robot_localization" type="navsat_transform_node" name="navsat_transform_node" clear_params="true">
    <rosparam command="load" file="$(find robot_localization)/params/navsat_transform_template.yaml" />
      <!--Placeholders for input remapping. Set your topic names as the "to" values.-->
      <remap from="imu/data" to="/imu/data"/>
      <remap from="odometry/filtered" to="/odom"/>
      <remap from="gps/fix" to="/fix"/>    
  </node>
</launch>

And these are the parameters for that

frequency: 30
delay: 3.0
magnetic_declination_radians: 0
yaw_offset: 0.0
zero_altitude: true
broadcast_utm_transform: false
broadcast_utm_transform_as_parent_frame: false
publish_filtered_gps: false
use_odometry_yaw: false
wait_for_datum: false
datum: [55.944904, -3.186693, 0.0]