Host a Git Repo on a Subdomain with Cloudflare

This site is hosted on Cloudflare Pages, but I have another repo on the same Gitlab account that I wanted to put on a subdomain of pywkt.com. Since Cloudflare is already managing my DNS for the site, I assumed I would just add a CNAME record for pywkt.com that pointed to the <repo>.pages.dev URL that Cloudflare gives me when I host a repo on Pages. This is the correct idea, but I just went about it the wrong way.

The following instructions assume you already have a domain in your Cloudflare account. You don't have to purchase the domain through Cloudflare, but Cloudflare should be managing the DNS records for the domain you want to use.

Log in to Cloudflare
Click 'Pages' in the left hand menu
Click the 'Create a project' button
Select 'Connect to git'
If your Git account isn't already connected, you will have to do that here. Once it's connected you'll see all the repos on that account.
Select the repo you want to host on a subdomain
When it asks for the domain you want to use, enter the domain with the subdomain.

The root domain must already be connected to your Cloudflare account. For me, I entered something like: whatever.pywkt.com

You'll have to either put in the build commands or have Cloudflare do it for you by choosing the type of site. For me it was a simple Create React App site so I just chose that.
It'll also ask you to confirm that a CNAME record will be added to your domain's DNS. Confirm that and in a minute or two it should be good to go.

Simple.

The way I was originally trying to do it was through the domain's DNS options. I had my repo hosted already by Cloudflare at a <repo>.pages.dev URL from Cloudflare and I was trying to add a CNAME with that as the value, but when I would visit the subdomain on pywkt.com I kept getting Cloudflare timeout errors and couldn't figure out why. Turns out you do it from the start of setting up the repo. And that's that.

Note: I may have the order of setting up build commands and confirming the DNS change mixed up. I just wrote this from memory, but will make a note to update that the next time I do this if it's backwards.