Non-secure HTTP notice

I have logged into eBay today and a notice states that every listing I have isn’t compliant with non-secure HTTP. Could someone please help me to resolve this as I have 3000 listings flagging up.

I have already adjusted listing multiple times for all their new rules.

Hi Ricky,

do you already know the overview/instructions here?:

Regards, Kristian

I had an out of date paid store design and had to restore the footer. It seems to have resolved the issue. Thanks for the help.