The front-end application is just a sample, meaning that you can build the front-end in the way you like the most!!
If you are a test net user request the source codes of the bridge and example front-end application by contacting us via email, in the slack channel, or from the contact button in the UI to request a redemption code.
Enter the repository.
cd 1DLT bridge
In the truffle-config.js
Inside networks, modify the mnemonic phrase and the address for the 1DLT node and the target chain (e.g., Ropsten).