Wait for them to ask. And don't put "references available by request" or something similar. If they want them, they'll ask.

Have some people in mind you could ask for references if they're needed. Ideally they'd be a previous employers in tech, but it can also be people you've volunteered for or worked for outside of tech. The most important thing is that they can vouch for you doing good work.

One thing I like to do is remind my references why I'm great:

Hey [name]! I'm in the middle of the interview process for [company] and was wondering if you'd be willing to act as a reference for me. I was hoping you could talk about [impressive things I did while working with you] and about how I'm [skills I have and showed them while working there]

Then when the people I'm interviewing with call them up, they already know what to say about me!