CODE EXAMPLE FOR PHP

Upload Webp to Wordpress

// add this code into your function.php file in theme editor

function webp_upload_mimes( $existing_mimes ) {
	// add webp to the list of mime types
	$existing_mimes['webp'] = 'image/webp';

	// return the array back to the function with our added mime type
	return $existing_mimes;
}
add_filter( 'mime_types', 'webp_upload_mimes' );