index.html holding page problems

While developing my site I’m using an index.html file that says “opening soon” and hoped to develop the wordpress site behind that, removing index.html when the site is ready for the public.

I’m having an issue where if I click on a link (read more or some such) I get the index.html because all of wordpresses links are aimed at https://www.mysite.com/?p=10 instead of https://www.mysite.com/index.php?p=10 and becuase the host serves index.html in preference to index.php I get the holding page.

How can I force WordPress to explicitly address its pages instead of pointing them at the directory?

Thanks for reading

DMA