To change the source code, fork this repository and work inside your own branch. Then send us a PR and wait for the CI to check everything. However, you'd better check changes first locally:
To report a bug, suggest new functionality, or ask a question, go to [Issues](https://github.com/teloxide/teloxide/issues). Try to make MRE (**M**inimal **R**eproducible **E**xample) and specify your teloxide version to let others help you.