TryItOnquine Challenge (based on this post and the ensuing discussion on chat -- also, much thanks to Dennis for TIO!)

The Challenge

Choose a language that's currently available on the TryItOnline site, for example PowerShell. Write code in that language on that page, that doesn't take any input, such that when the Run button is clicked, the output on that page is the exact same as what is in the "Plain URL" field when the Save/Store button is clicked instead.

For a fictitious example, suppose that aaa was the code for a solution to this in PowerShell. Then, the result of clicking Run with aaa as the code on https://tio.run/#powershell should output https://tio.run/##K8gvTy0qzkjNyfn/PzEx8f9/AA, which is also the "Plain URL" field when the Save/Store button is clicked.

Scoring

The resulting URL is your submission to this challenge. The winner is the shortest URL measured in bytes. For the example above, the URL https://tio.run/##K8gvTy0qzkjNyfn/PzEx8f9/AA is the submission to the challenge, at 44 bytes. The shortest URL that fulfills the rest of this challenge wins the challenge and earns brownie points (points not redeemable). Given that there is a distinct minimum possible length, if two submissions tie in length, the earlier submission wins.

URL Generation

This is the start of the URL generation algorithm in the repository. You can see how the main code area is taken, any extra elements are appended, the string is deflated and Base64 converted, and then ## prepended, etc. I won't go into full detail here; part of the challenge is to parse and understand how the URLs are generated in order to exploit any potential quirks in said algorithm.

Rules / Clarifications


The actual code should take no input and produce only the quine-URL as output.
-- This means the only text fields that should be populated when clicking into the URL are the Code, Header, Footer or corresponding "Compiler Flag" fields; the Input and Arguments fields are forbidden and must remain empty/unused. Clicking the Run button should only change the Output field. For this challenge, the Debug field is ignored in all situations.
Usual quine rules apply to the code to the extent possible (for example, the code cannot read its own source code via .code.tio).
Please include a description of how the code works in your submission.
Submitting a "cheaty" quine by submitting a Git pull request to the TIO repository to create a "trick" URL or shortcut or the like is not allowed.
Similarly, submitting a pull request to update a particular language to produce a "trick" URL is not allowed.
Please be nice to Dennis' servers and don't abuse them or attempt exploits for the sake of this challenge.
Python 2, URL length = 170 bytes

https://tio.run/##K6gsycjPM/r/v9hWqQDCjqlISwPhYlvVIuvM3IL8ohKFpMTiVDMT64KizLwS9YySkoJiK339ksx8vaLSPH1lZXVtiAK9JDOT1Lzk/JRUDY1iVdViTT0YT70qJzNJXVMz2shK1yRWE2aHEkUW4Db//38A




s="python2\xff\xffs=%r;import base64;print'https://tio.run/##'+base64.b64encode((s%%s).encode(('zlib'))[2:-4])\xff\xff";import base64;print'https://tio.run/##'+base64.b64encode((s%s).encode(('zlib'))[2:-4])


Try it online!

This relies on three coincidences:


The default zlib level 6 happens to give the same results as zlib level 9 for this string, modulo the header that I strip.
The compressed length is divisible by 3, so base64 does not generate any = padding characters.
The base64 output does not contain any + characters.