The data from my personal TIL site is now migrated. Here's how I handled URL redirects in Cloudflare
To set up a subdomain redirect with Cloudflare while preserving the request path and parameters, you can use Page Rules.
In the Cloudflare dashboard for your domain, click on the Page Rules link in the Rules section of the main navigation menu on the left of the page.
Click on the Create Page Rule button to start configuring the redirect.
In the If the URL matches field, enter the pattern for the URLs you want to redirect, using a wildcard (*) to capture the path and query string. In this cae, the pattern is:
Now click on Add a Setting and select Forwarding URL from the dropdown menu.
Select 301 - Permanent Redirect from the Status Code dropdown.
In the Enter destination URL field, enter the URL where you want to redirect your requests to, using the $1 placeholder to preserve the query string.
Click on Save and Deploy to create the Page Rule and enable the redirect.