When building the explorer in a fresh new environment, cargo run will fail due to missing dependencies on openssl and protoc libraries. Have discussed this with Tobias who advised to add this to the README.

use a fresh new dev environment
cd explorer-exe/
cp config.dist.toml config.toml
cargo run and observe the build failure
sudo apt install libssl-dev
sudo apt install -y protobuf-compiler libprotobuf-dev
cargo run
Go to http://localhost:3035 and ensure explorer loads locally