Select File
You can take an example of file here.
// src/actions/import/do.php $request = json_encode([ 'name' => 'Import', 'files' => [ [ 'fileName' => $fileName, 'fileImportPage' => [ 'hasHeader' => true, 'columnMappings' => [ [ 'columnName' => 'First Name', 'propertyName' => 'firstname', 'columnObjectType' => 'CONTACT', ], [ 'columnName' => 'Email', 'propertyName' => 'email', 'columnObjectType' => 'CONTACT', ] ] ] ] ] ]); $hubSpot->crm()->imports()->coreApi()->create($request, $fileName);