Use this command to get the timestamps for the given Discord snowflake. This command requires the Discord snowflake of the message you would like to get the timestamp for.
To obtain the Discord snowflake for a message, right-click on the message and select "Copy Message ID"
Command:
!ta timestamp <DISCORD_SNOWFLAKE>
Example:
!ta timestamp 1053095677346988144
Example image for Discord message 'right-click' menu