You can customize the page by editing the generated output .html file. There is currently no “templated” way to modify the page in source project, so when you re-export, it will copy over the changes in the .html file. In order to make your changes persist, I generally copy the main .html file over to some other name, like index.html, so that it will not be overwritten after I do some modifications to it.
Inside the html file you can find the button elements and e.g. add a style=“display:none;” setting to them, or comment them out by enclosing them in a block, or just delete the lines.
I know this is somewhat of an older post, but I want to do the same. I want to remove the buttons from the html page, but when I modify the file directly then the game doesn’t launch anymore. Is there a way to go around this?