The How to Open a Homebrew Pull Request documentation is great. This doc assumes you've already created a fork of homebrew-core named after your user and a branch tracking the master of the fork.
cd (brew --repository homebrew/core)
brew update
git checkout phette23 # tracks master branch of fork
git pull # might need to sync fork to homebrew?
set FORMULA marcli # name of the project you're bumping
set VERSION 1.1.0 # semantic version
brew bump-formula-pr --no-fork --url https://github.com/account/$FORMULA/archive/refs/tags/v$VERSION.tar.gz project