NameCheap gives you a free SSL certificate only for the first year of hosting then you have to buy one for around $10 and install it.
But I will show you how to get Totally Free SSL certificate and install it on Namecheap hosting.
Run the following command
curl https://get.acme.sh | sh
.acme.sh/acme.sh --issue -d wpruns.com -w /home/respxpxr/wpruns.com/
You can see the generated certificate and the key
Your cert is in /home/respxpxr/.acme.sh/wpruns.com/wpruns.com.cer
Your cert key is in /home/respxpxr/.acme.sh/wpruns.com/wpruns.com.key
The intermediate CA cert is in /home/respxpxr/.acme.sh/wpruns.com/ca.cer
And the full chain certs is there: /home/respxpxr/.acme.sh/wpruns.com/fullchain.cer
Now go to cPanel and open the SSL/TLS page
Select the domain name you want to install the SSL
Copy the content of /home/respxpxr/.acme.sh/wpruns.com/wpruns.com.cer certificate to Certificate: (CRT) text box
Copy the content of /home/respxpxr/.acme.sh/wpruns.com/wpruns.com.key key to Private Key (KEY) text box
Now click the Install Certificate button