Whois script bash

I have made whois script in bash:

#!/bin/bash

# Store the list of domains in an array
while read domain
do
  # Output the header
  echo "Domain,Registrar,Creation Date,Expiration Date"

  # Perform a WHOIS lookup for each domain
  whois_output=$(whois "$domain")

  # Extract the relevant information from the WHOIS output
  registrar=$(echo "$whois_output" | grep "Registrar:" | awk '{print $2}')
  creation_date=$(echo "$whois_output" | grep "Creation Date:" | awk '{print $3}')
  expiration_date=$(echo "$whois_output" | grep "Expiration Date:" | awk '{print $3}')

  # Output the information in a row
  echo "$domain,$registrar,$creation_date,$expiration_date" >> domain_info.csv
done < domains.csv

The output is coming in vertical way:

Facebook.com
Creation date
Update date


And I want data in horizontal way like: 


Facebook.com,creation date , update date

this is the output I want & this the output I am getting

For the vertical to horizontal conversion, I think the simplest fix is to simply remove the newlines which can be done by piping to tr command:

# Output the information in a row
echo "$domain,$registrar,$creation_date,$expiration_date" | tr -d '\n' >> domain_info.csv