Individual Instagram Stories have a limit of 15 seconds for video content. However, using Instagram’s segments tool, you can record a longer video. The Segments tool then automatically splices this longer video into 15 second segments, that will play consecutively for your viewers. To do this, simply:

The correct answer is to hold down the record button for the duration of your take. This is how Instagram's native Stories feature allows users to record longer videos, automatically segmenting them into 15-second clips that play sequentially. Uploading a longer video into a bulk uploader or adding it to a branded template are not features that directly enable the automatic segmentation of longer videos within Instagram Stories. While 'Story Settings' exist, there isn't a specific 'Segments' option to enable this functionality; it's an inherent behavior of the record button.