Backend hosted on EC2 refuses connection

I have launched EC2 instance and cloned my backend (Node.js) from GitHub, but i cannot connect to it neither via EC2 Console link (public IPv4 adress/public IPv4 DNS) nor via fetch from my front-end app (hosted on another service) i have the same error: ERR_CONNECTION_REFUSED. Instance is running, both status checks passed. Saw a similar question, unfortunately without a solution to the problem, it was advised to run a command wget http://localhost to check if application is working, and here's my output:

Resolving localhost (localhost)... 127.0.0.1
Connecting to localhost (localhost)|127.0.0.1|:80... failed: Connection refused.

.

It might be useful:

Network ACL has 2 inbound rules:

• default (rule number *), which denies all traffic
• i added rule with number 1, which allows all traffic

Also i have 2 security groups:

• default, which i believe directs all traffic at itself? (it's source is self ID)
• second group was generated on instance initialization and i added my own rules later, which allows all traffic (e.g. rule type HTTPS, protocol TCP, port range 443, source 0.0.0.0/0)