Follow the following steps:
Enter the cpanel. If it is a vps, click on list account or account list and enter the individual panel of the domain where we are going to install it.
Click on SSL/TLS
If it is a text mode certificate, click on Manage SSL
Here we paste the certificate in its three elements: Domain. We select the domain to install the certificate. Certificate: (CRT), here we put the certificate that the certifier has sent us. Private Key (KEY). This is the private key of the certificate that has been generated from the crc that we have sent to the certification provider, it will appear in the panel of the same. Certificate Authority Bundle: (CABUNDLE). The certificate provider must indicate it to us, it will surely come on their website or in the email where they have sent us the certificate data.