How to make a 301 redirect from one site to another site with https?

Question

htaccess

It is necessary to make a correct redirect from one site to another site with https. I do it as follows, but the redirect happens to a site with http, and I need it with https:
RewriteEngine on
RewriteCond %{HTTP_HOST} ^site1.com
RewriteRule ^(.*)$ https://site2.com/$1 [R=301, L]
When typing a site through site2.com , the site does not open because it is blocked by the provider and opens only with https. The redirect inside the site from http to https was done correctly, but in order to get to site2.com, the redirect from site1.com must be with https i.e. https://site2.com