Hello @Sajjadmosaheb ,
I had a personal account with Gmail I used with the Send Email node.
Since May 2022, Google changed its policy and does not allow third-parties to send emails through its services using username and password only.
Have a look at this post and follow this link: https://myaccount.google.com/lesssecureapps
If your email address is personal, I would consider creating another address with another provider.
Have a nice weekend,
Raffaello