Click on Products and choose Import task in your Dashboard.
You need to add the name of your task and choose the type of the import task.
UPSERT: upload new products + update existing*
UPDATE: just update existing products*
UPLOAD: just upload new products*
* if the task and the file are proper for this. If you are unsure whether you can add to Syncee your supplier feed properly, or if you have any question please send us a message and we help you.