Date of publication missing on web page when in AGLC3

I insert the publication date of the web page, however when I refer to the reference in my footnotes in AGLC3 format the publication date doesn’t appear. When I switch to another style it is there. How can I fix this?

You should edit to open each of the output styles and compare the two footnote templates and perhaps copy and past the one that works to the one that doesn’t.  I assume that AGLC3 doesn’t include the date field you need, while the other template in the other style does.  

Detailed self help info to edit output styles are available here, or you can ask again here, but I am not familiar with this style and its requirements, so I can’t edit it for you without the information.