How to redirect http to https on a fully static web page

Hello this is my first question I'm asking here.
Please advise if you think I can improve the question.

We're hosting our web page with the OVH web hosting solution "Professional 2010"

And we activated https:// access via LetsEncrypt.

The page we have is a fully static page:

Is there any way I can achieve following:

Anybody who accesses our site with http://oursite should be redirected to https://oursite

If I had apache / nginx I would know how to do it, but I'm not sure how to achieve this with the OVH "Professional 2010" solution.

Any advice is welcome