Page dont work without adding HTML file name

hello guys i have a problem that when i go to the link generated by github pages it does not take me directly to my website unless i add the html file name such {/simo.html } in this one https://ammar1999-a.github.io/siom-test/simo.html

but i made another repository when i click on the link generated by github pages it takes me to my website without adding the html file name so plz help with this

Pages will look for a file called index.html, index.md, or README.md to serve by default. As you only have a file called README.md Pages is serving that when you visit your site. Your other files are available if you visit them directly.

To serve your simo.html file when you visit your site you’ll need to rename it to index.html.