Make a social field required in WC Vendors settings form

functions.php

// To make a field required for social media you will need to use the social settings id 
// Hook with 'wcv_social_field_(socialfield id). 
// In this example it is 'instagram'

add_filter( 'wcv_social_field_instagram', 'make_required' );
function make_required( $field ){
	$field['custom_attributes'] = array( 'required' => '' );
	return $field;
}