In order to activate an SSL certificate, your client needs to access list of their services and click on "View Details" button next to the ordered certificate.

• Next, they will need to click "View certificate details", and then - "Configure certificate". They will see a window with SSL activation fields.
  
• Here, they will be prompted to input the CSR code (obtained from the web-server their domain is hosted on), select a web-server type, and fill in valid admin contact info.
• Admin contact info will be pre-filled from the customer's profile in WHMCS.
• In case CSR code is ok, your client will see the list of available DCV options on the next page. Those are, basically, an HTTP-based validation or an approval email.
  our client can choose any of the listed emails to receive Domain Control Validation email on that address, or select the HTTP-based DCV. If the HTTP method is selected, no email is to be sent for validation, however your customer will need to submit a certain text file into a particular directory of the website (/.well-known/pki-validation/).

Note: Name and contents of file will be shown after they click "Submit" and activation data gets transmitted to the Certificate Authority. Also, the file contents can be checked in customer’s area by viewing the certificate details for the SSL that is being activated.

Note: If you have activated the certificate with domain.com or www.domain.com indicated as FQDN in your CSR code, please make sure that the file is available via http://domain.com/.well-known/pki-validation/file.txt . In this case, www.domain.com is considered to be under your control as well.

Content of the file should not be changed in any way, as Sectigo validation system is case sensitive.

A further process is between you or your customer and the Certificate Authority. You are to receive an approval email, and to confirm it. Once done, the certificate will be sent to the admin contact email address for the SSL order within 10-15 minutes. Otherwise, some documents request will be sent to the order email for OV or EV certificates.

Important Note: 

Language variables containing strings with instructions to HTTP-based validation and with file contents are stored in /modules/servers/namecheapssl/lang/English.php. If you are using other language you need to create
/modules/servers/namecheapssl/lang/%yourlanguage%.php and change values of the following variables to corresponding phrases in your language: $_MOD_LANG['ncssl_http_based_validation'] ,$_MOD_LANG['ncssl_show_validation_file_contents'] , $_MOD_LANG['ncssl_custom_phrase_sslcertapproveremaildetails'],$_MOD_LANG['ncssl_custom_phrase_sslconfigcompletedetails']