Select Header is the second tab under Sheet Settings → Import Steps. On this step, users confirm which row of their file holds the column headers.
After a user adds a file, they select the row that contains the column headers before the importer moves on to Map Columns. The import flow runs in this order: upload, select the header row, map columns, then Verify Data.
Skip this step
Hide the Select header row page from users.
Help text
Add help text to the header selection page, separately for each language. The help text supports Markdown formatting for bold, italics, and links.
Default row selection
Choose which row is pre-selected on the header selection step. If you leave it empty, the first row is selected.
If your users’ files usually have a title or blank rows above the headers, set the default_header_row option so the right row is already selected on the Header Selection page. Rows are 1-indexed.
Also available as an installation parameter: default_header_row. See Options on the Install the Code page for how to pass this option in each framework.
Show encoding option
Show or hide the character set selection list to users. UTF-8 is the default.
Show switch row/columns option
Show or hide the option that lets users switch rows and columns.
Hiding the options you don’t need removes non-essential choices from the importer and makes the experience cleaner for your users.
Track drop-offs
Import Analytics shows how many users reach and complete header selection, and how long they spend on it. 
