I got it through the F-Droid app. The creator has a gitlab repo for it, but I could only find direct download links on the f-droid website. I hope that's what you needed!
I've been looking inbetween real work, but so far I haven't found anything built-in that is useful.
I did, however, find that on my mido running LOS-15.1-Official, Call Recorder 1.6.5 works perfectly.