Google Less Secure Apps Enable. A less secure app (lsa) is an app that connects to google accounts using only username and password verification for access and not oauth. To enable the less secure application on gmail and g suite, you need to follow a few simple steps mentioned below.
Google has many special features to help you find exactly what you're looking for. Gmail starts to block less secure apps: Next to “allow less secure apps:
Off,” select the toggle switch to turn on.
Visit the display unlock captcha page […] Then allow less secure apps should be turn on by click on the toggle button; By default, google only accepts oauth 2.0 authentication. Test your mail application again.