The first thing you have to know, you can only use Syncee if you have a Shopify store and you log in via your Shopify admin.
Follow these instructions:
1. Log in to your Shopify store admin page
2. Click on apps
3. Click on the Syncee app (this way you log in automatically to Syncee)
Please do NOT reinstall the app, just write us and we help you to solve this issue.
If these do not help you, or you still have an issue with the login, take a screenshot and send us an email to firstname.lastname@example.org.