If you see an error on your browser that states your website is not secure, try accessing your website via HTTP protocol (unsecured connection), such as http://www.domainname.com.
You must have a SSL certificate installed in order to access your website via HTTPS protocol (secured connection), such as https://www.domainname.com.
If you do want your website to work via the HTTPS protocol, here are some steps to help you:
1. Make sure you have a SSL certificate installed for your account. You can purchase one from Hostinger (Members area > SSL section), or purchase a certificate elsewhere. After your certificate is activated, you can install it from your control panel > SSL section.
2. Once the certificate is installed, you can access your website via HTTPS protocol, such as https://www.domainname.com.
3. If you are getting a "website is not fully secure" error, it means that your website's resources are not loaded through HTTPS protocol. This problem can be solved by modifying your website's code manually, or through the back-end on applications such as WordPress. Here are some tutorials to help: https://www.hostinger.com/tutorials/wordpress/how-to-use-https-on-wordpress . You can check all problematic resources at https://www.whynopadlock.com/
4. Lastly, if you want your website to be auto-redirected to HTTPS, check out https://www.hostinger.com/tutorials/ssl/forcing-https and https://www.hostinger.com/tutorials/wordpress/how-to-use-https-on-wordpress for some examples.