EC2 instance has apache2 server installed, but I can’t connect to it

I have an EC2 instance running Ubuntu 18.04, with apache2 server. I am able to connect to it via PuTTY and via FileZilla and view the server. The server is running, there is the index.html file that’s created by apache2 under /var/www, but still when I type in my public IPv4 address in the browser, I cannot connect and view the apache2 welcome page (Cannot connect to it)

What may be the cause? Is it possible that it’s because I am on free tier and I am already running another EC2 instance? (Which is working fine)