SSL certificate not working even if installed

I bought my domain on GoDaddy.

I used the basic plan for SSL here on Cloudflare (0$) but it’s not working.
Changed the Name Servers from GoDaddy’s to Cloudflare’s but still not working.

How can I make my website secure?

Can you please clarify what mean by doesn’t work? Cloudflare offers free edge SSL certificates, but you will need a certificate on your origin server to have full SSL.