I'm setting up an Apache server in Debian.
When I access https://.../index.php from Chrome, I get the following result:
Somyquestionsare:
DoInecessarilyneedapaidcertificate,oristhereanotherpath?
https to http , is this possible in Apache? Each different browser has a list of the certificates you trust. In general, all paid certificates are considered trusted by major browsers. Already for the free certificates, you will have variations.
The best known of free certifiers should be Let's Encrypt. They have a page listing which browsers trust your certificate .
Note that most browsers and other software rely on them. Only few big players on the market do not have confidence (like Windows Live Mail).
Now to change the protocol of access to your page, it is rather possible to do, quite simply. I am not an expert in Apache but if with .htaccess or similar you can do a server-side redirect, that is enough. Please note that without https, all traffic to your site can be read by intermediaries.
You can place a free certificate, learn about: Let's Encrypt is a free, automated, and open Certificate Authority
Install Install Let's Encrypt to Create SSL Certificates
Configure for Apache SSL Certificates with Apache on Debian & Ubuntu
HTTPS Redirection for HTTP (.htaccess)
RewriteEngine On
RewriteCond %{HTTPS} on
RewriteRule (.*) http://%{HTTP_HOST}%{REQUEST_URI}