Captcha

Go to hcaptcha.com and create a free account. Make a sitekey and a secret. Add domain.tld to the sitekey. Optionally, increase the difficulty threshold. Making it even harder for bots.

Edit your .env file:

KBIN_CAPTCHA_ENABLED=true
HCAPTCHA_SITE_KEY=sitekey
HCAPTCHA_SECRET=secret

Then dump-env your configuration file:

composer dump-env prod

or:

composer dump-env dev

Finally, go to the admin panel, settings tab and check "Captcha enabled" and press "Save".