No, I can’t download a 32 bit version of the Fennec apk (assuming it exists?) since I can’t find the URL for it.
The F-Droid app (also side-loaded) doesn’t give me an URL at all. I have to use the external service like https://apt.izzysoft.de/fdroid/index/apk/org.mozilla.fennec_fdroid?repo=archive which allows me to drill down to Version 68.12.0 (2020-08-29) and the URL https://f-droid.org/archive/org.mozilla.fennec_fdroid_689420.apk which unfortunately is a 64 bit version I can’t side-load (see thread on sideloading Fennec apk on ChromeOS (Lenovo Chromebook duet latest) fails : chromeos for the gory details)
So the question is, how can I discover the URL of an apk on the F-Droid repo, without going through the F-Droid application, preferably by just browsing F-Droid Archive (which currently is a 404) or using the Search option there, which currently, unhelpfully, redirects me to the current Fennec F-Droid | F-Droid - Free and Open Source Android App Repository rather than the archive repo.
The https://f-droid.org/archive/org.mozilla.fennec_fdroid_689420.apk is not the droid I was looking for, being 64 bit.
Potentially, a related issue is Fennec v62 only available in ARMv8 64bit, not ARMv7 - #6 – perhaps the builds have not been resumed, after all.