You never call any of those files directly. You only need to fill out the proper paths in the edit integration in admin like maybe so since I dont have your true paths here all anyone can do is make suggestions but this is what it should look like
server path to forum
/home/*****/public_html
server path to photopost
/home/*****/public_html/Photopost/
url to forums
http://www.domain.com
url to photopost
http://www.domain.com/Photopost
url to data directory
http://www.domain.com/Photopost/data/
then turn on the 3 vb3 integration switches