In the Layout Editor, select the component that triggers the form or action you want to add the current date and time to.
Click on the plus (+) symbol in the Components panel and select Special Values -> Current Date/Time component.
In the panel on the right of the Layout Editor, select the target column where you want to record the current date and time.
You can set up your target column as a Date & Time column in the Data Editor to set your preferred date/time format. Otherwise, you'll have a record that looks like this: 2020-04-01T11:00:21.496Z
Note that when creating Date and Time values, there is a Respect time zones box that is checked automatically. This considers the user's time zone when calculating the value.
This box will not appear if your table is Google Sheets.