Git - How to make custom alias function always available? - bash

Question

I have a script that I've made that creates a repository locally, creates first commit and creates the remote repo. Here it is:
#!/bin/bash
function create-repo {
inside_git_repo="$(git rev-parse --is-inside-work-tree 2>/dev/null)"
# check if we already inside a repository
if [ "$inside_git_repo" = true ]; then
echo "Error: It is not possible to create a repository inside another one"
else
#check if the name of repository is not null
if [ "$1" = "" ]; then
echo "Error: Missing one argument (Repository name)"
else
#creating repository folder
echo "Repo will be created with the following name: $1 "
mkdir "$1"
cd "$1" || exit 1
echo
#Create a README.md file to push to remote
echo "# $1" >> README.md
echo
#initializing repo
git init
echo
#staging and commiting README.md file
git add README.md
git commit -m "first commit"
echo
#username in github
username="alanwilliam"
#secret token of github API
token="PUT HERE YOU SECRET TOKEN"
#json that will be sent to github API
json="{ \"name\":\"$1\" }"
#Curl command that does the magic to create the remote on github
curl --user "$username":"$token" --request POST -H "Content-Type: application/json" -d "$json" https://api.github.com/user/repos
echo
echo
echo
#adding remote and pushing
git remote add origin https://github.com/alanwilliam/"$1".git
git push -u origin master
fi
fi
}
This code is working just fine - it is perfect for me. I've put it inside a file called .custom_aliases and it worked. However, in order to git detect this file and make the command available, every time that I open git bash, I need to type
source ~/.custom_aliases to be able to use the command in script, which is annoying.
Is there a way to make it always available, so I don't have to type the source command every time I open git bash?