Converting a DATETIME obj to a TIMESTAMP obj

Let’s say you have a some sort of date coming in as a string:
'2021-12-16 12:49:46.993539'

You can parse it via:
PARSE_DATETIME_ISO8601( '2021-12-16 12:49:46.993539' )

This gets you a DATETIME obj… To convert it to a TIMESTAMP, you have to add some sort of timezone:

SELECT PARSE_DATETIME_ISO8601( '2021-12-16 12:49:46.993539' ) AT TIME ZONE 'America/Los_Angeles' ;

Reference docs:
PARSE_DATETIME_ISO8601(string)
AT TIMEZONE