To run GSA Website Contact Software you'll need a license which you can acquire here: GSA
In addition, you' need captacha breaking sofware and proxies.
These are our recomendations:
ProxyScrape HTPPS Proxies for GSA Website Contact
ColdProxy for IPv6 Proxies for XEvil Captcha Breaker
We recomomend using both in tandem for the nest success rates!