Development of a smart contract for exchange on the BSC network + test platform

A smart contract needs to be developed for the bsc network (testnet) for exchanging our test token for usdt or other stable tokens.
Requirements for the contract:
- Token sale/purchase operation without gas fees

- Setting and calculating the price according to our rate specified on the backend (currently it can be set manually)

Work process.
1. Issue tokens for further exchange
2. Writing the contract (there is a ready guide for students where everything is described step by step)
3. Deploy the contract on the test network for testing
4. Development of a no-design application. Purely to test the operation of the smart contract online.
You can take any open code from GitHub, for example https://github.com/auser/token-swap-dapp

I will say right away that this work is a test.
I plan to find a developer for ongoing collaboration on tokenization. The next stage of implementation will be transferring to the settings already on the finished smart contract application and deploying the contract on the main network.

Preference will be given to a developer who is ready to go for online calls to discuss project details. There will be revisions, but also adequate feedback. I look forward to your proposals.