This is how I manage multiple gitconfig files

.gitconfig

[alias]
	c = checkout
	cm = commit -m
	s = status
	b = branch
	hide = update-index --assume-unchanged
	unhide = update-index --no-assume-unchanged
	hidden = !git ls-files -v | grep ^h
[includeIf "gitdir:~/Workspace/work/"]
    path = ~/.gitconfig-work
[includeIf "gitdir:~/Workspace/apps/"]
    path = ~/.gitconfig-personal
[includeIf "gitdir:~/Workspace/personal/"]
    path = ~/.gitconfig-personal
[init]
	defaultBranch = main
[push]
	autoSetupRemote = true
[pull]
	rebase = false

.gitconfig-personal

[user]
 	name = Phan Khắc Đạo
	email = [email protected]
  

.gitconfig-work

[user]
	name = My Work Name
	email = [email protected]