Mail Not Send Using SMTP

Hello Folks,
I try to send an email using SMTP in asp.net but I got an error as per below.

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Authentication Required.

I got the above error after a Google No Longer Support in Less Security.

I tried many ways to mail send but I could not send the email using SMTP after google was no longer supported it.