Plugin integration problem: index.php not displaying

I was hoping someone could kindly assist with a problem I have been having integrading widgets/plugins into my wordpress page.

-Widgets added to side bar (OK)
https://www.function2.com/wordpress (example test address)

-Example ‘subscribe2’ and ‘sidebar login’, the problem is that they not working correctly with out the ‘/index.php’ file extension on the url.

For example,
https://www.function2.com/wordpress <–widgets are not working.
https://www.function2.com/wordpress/index.php <–widgets are working.
https://www.function2.com/wordpress/?page_id=2 <–widgets are not working.
https://www.function2.com/wordpress/index.php?page_id=2 <–widgets are working.

But I can not just redirect the url like ‘../wordpress’ to ‘../wordpress/index.php’ because it goes to worng address when I click any post.
ex: “https://www.function2.com/wordpress/?p=14” this url will redirect to “https://www.function2.com/wordpress/index.php/?p=14” which is not opne correctrly ( should be “https://www.function2.com/wordpress/index.php?p=14” – no “/” between ‘index.php’ and ‘?p=”)
That’s why I can not use redirect url option eather.

I don’t know what is the real problem and cause this problem, but the problem will be solve if all the pages show the file extension without hiding.

Again, hiding the file extension in the url is causes the applications not to work. Is this an issue with my host (IX Webhosting) or is there something that I’m not doing correctly?
Or, please let me know if any one knows how to NOT hide the file extension. -need to show the file extection like ‘../wordpress/index.phph” and ‘../wordpress/index.php?p=14’.

Any help would be greatly appreciated!

Vickie