Here is a list of urls to the Librelink app. You don't need to install this app, but download it and then let Juggluco open it. Juggluco will then extract a library out of the APK file and use that for the interpretation of data it receives from the sensor. Because it is of someone else, the library is not included in Juggluco.
Starting with version 2.2.1, Juggluco works directly with US sensors (also used in Australia and Canada). For this you need a library out of Libre app version 2.5.2, 2.5.3 or 2.7.1. Newer versions don't work. For example you, can download https://apkpure.com/freestyle-libre-2-ca/com.freestylelibre2.app.ca/download/6373-APK and open the apk in Juggluco. For arm64, you can also download the xapk from https://m.apkpure.com/freestyle-libre-2-us/com.freestylelibre2.app.us/download/6886-XAPK, unzip it and open config.arm64_v8a.apk in Juggluco.
If you are certain not to use a US like Freestyle Libre 2 sensor, you also use a library from an older version of Abbott's Librelink app. This has the advantage that it doesn't contain a root-check and is much faster and, because the root-check is repeated every minute, uses much less battery power. Here are some examples of such an older apk:
https://m.apkpure.com/freestyle-librelink-es/com.freestylelibre.app.es/download/5933-APK
https://es.apksum.com/download/com.freestylelibre.app.hk_2.4.2_free
https://www.apksum.com/download/com.freestylelibre.app.sg_2.4.2_free
https://www.apkfollow.com/download/arb_new_com.freestylelibre.app.de_2020-05-19.apk/
https://apkplz.net/download-app/com.freestylelibre.app.au?version=3444046
You can check if an apk came from Google Play at the following url: https://apkpure.com/apk-signature-verification