setting google workspace email in CodeIgniter website

my website s built on CodeIgniter (PHP) I have an issue with the SMTP email from Google workspace after replacing it instead of an old email that was no longer valid, this email billing@brunokens}was set up to send notifications to my students after purchasing my study exams, and right now I have created a new google workspace email "billing@brunokens" I have replaced the SMTP details but cannot send messages yet, I need to fix this issue. I need to fix it remotely via anydesk , and I will help you to get access to the full code! Best Regards