Contact Form 7 – reCAPTCHA v2 brings the use of reCAPTCHA v2 and the
[recaptcha] tag back.
When you install the plugin, you need to select reCAPTCHA v2 as your reCAPTCHA version.
If this plugin is installed before updating Contact Form 7 from v5.0.5 to v5.1.1, it will carry over your old API keys.
Then you will be able to use Contact Form 7 with reCaptcha v2 as you did previously and use
[recaptcha] tags in your existing or new Contact Form 7 forms.
Once installed and configured Contact Form 7 – reCaptcha v2 offers the same reCaptcha functionality you are used to in previous versions of Contact Form 7.