The first thing you got 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, Login 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 have an issue with the login take a screenshot and send us an email to firstname.lastname@example.org