Primarily check the presence of an installed SSL certificate in SSL settings... If there is no certificate, you need it install.
If the site is tied to the address or protocol used, then the redirect setting must be done in it. Additional inclusion of redirection in the control panel can lead to endless redirects and problems with the display of the site. For some popular CMS we have instructions for setting up to work over HTTPS:
To set up a redirect, do the following: