I'm just getting started with Landing Pages to create a custom preference center using ampscript/api calls. I've coded the page to display subscriber data upon first view. When I look at the "subscriber preview" everything works fine and subscriber data populates the form. But when I go to the link of the ACTUAL landing page no data populates the form. I have appended URL variables. I have sent myself an email that included the landing page link. Outside of the "subscriber preview" no data is being pulled.
What am I missing here? Thanks,