Google-Apple Mail-Gmail

[Hysteresis]

I have an iMac(OS Yosemite) with Google installed. I have used Apple Mail with Gmail for years. I had to change my Google Password which was no problem but it obviously stopped the Apple Mail/ Gmail operation. Clearly it was necessary to change the Password in the IMAP and SMTP setup using the new Google password.
Have tried many times to connect the Apple Mail/Gmail communications with the new password and still the Apple mail does not connect to Gmail.
All of the settings in the Connect Doctor are correct as it all worked with the old Password.
Anyone advice on what I can do or try to get the system operation.
Clearly I can get my mails through Google but the Apple Mail is far more user friendly that Gmail.
A tutorial on You Tube did not help.

 

[flameport]

Gmail and other Google services do not generally support singing in with just a password now, as it's massively insecure.

You will have to use an updated app which uses modern authentication methods.

Less secure apps & your Google Account - Google Account Help

To help keep your account secure, from May 30, 2022, Google no longer supports the use of third-party apps or devices which ask you to sign in to your Google Account using only your use

support.google.com

 

[Hysteresis]

Does this mean that Apple Mail is considered a 'Less Secure App'??
The article you have been kind enough to forward suggests that Google have added security to their their Account system which considers AppleMail as a none secure app and that a solution could be to ensure my iMac should be running the later version of Apple's OS.
Well the problem I have here is that my iMac can't update to later version of the OS than Yosemite. Apple score again my making users by yet another Desktop.
Is there any way I can install the older version of Google back onto my machine??