Function cast in teradatamlspk also accepts format argument, use it for TimestampNTZType, TimestampType.
format option is optional.
PySpark
pyspark_df.select(pyspark_df.col.cast(TimestampNTZType()).alias('dt'))
teradatamlspk
teraspark_df.select(teraspark_df.col.cast(TimestampNTZType(), 'YYYY-MM-DD HH24:MI:SSTZH:TZM').alias('dt'))