404 on blog home

I started wordpress a while ago and a few things start to work. Here is what I don’t seem to be able to fix:

When on the blog at
https://www.wellnessmaster.com/blog/index.php
if you click on “Blog home” you get this message:

“Forbidden
You don’t have permission to access /blog/ on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
Apache/1.3.33 Server at https://www.wellnessmaster.com Port 80″

I get a similar message when I am in wp-edit and click on “view site” to check the result on a change I made.

I both cases what happens is that instead of landing on the home page of the blog at https://www.wellnessmaster.com/blog/index.php the /index.php is ommited and the browser lands at
https://www.wellnessmaster.com/blog/
What should I change to come to the proper home url?

The siteurl seems to be correct and has no /index.php.
Is there anything to add/edit in the .htaccess file or anywhere else?

WP is great but my ignorance makes the start a bit
painful ??
Any help is welcome.
Thanks