This Tool , Uses SubFinder and AssetFinder To Fetch SubDomains and Takes Them To Httpx Tool
Step 1 : Install Python3 and Go Lang
Install Go in Linux ===> https://www.youtube.com/watch?v=InffXO7V8_M&list=WL&index=1
Step 2 : Install AssetFinder
Step 3 : Install SubFinder
Step 4 : Install Httpx
Step 5 : pip install -r requirements.txt
Step 6 : python3 validsubs.py -u site.com