It attempted to download the file from Github and failed. You can do as the error says and re-run configure with NOISY_BUILD to see if it provides further information.
You should also be able to just stick the URL into a web browser, although you may then have the problem of copying it from the download machine to the target one.
If you had provided the screen the output as plain text, I would have tried that myself.
I would not have expected it to, as all you have done is to download, and probably not even into the right directory. You haven’t attempted to configure and build Asterisk.
All the test was trying to do is check whether it was downloadable, to your machine.
Did it take a long time to download? You might be exceeding a timeout. Otherwise, you will need detailed debugging to work out what is going wrong.
Downloading the file doesn’t automatically make the process start over, nor does the configure script look for it where you downloaded it. Putting the file, with the correct file name, in the proper directory and running configure again should find it.
from what I’ve verified, the files: jansson-2.14.tar.bz2.2 and jansson-2.14.tar.bz3 are still in the directory: /usr/src/asterisk-20.0.0, in which case I should remove 2.14.tar.bz2 .2 and move only 2.14.tar.bz3 to /tmp/ ?
rm /usr/src/asterisk-20.0.0/jansson-2.14.tar.bz2
mv jansson-2.14.tar.bz2.3 /tmp
cd usr/src/asterisk-20.0.0: ./configure
You should transfer the complete version of the file, under whichever name it is actually stored, to /tmp/jansson-2.14.tar.bz2. Note that I haven’t analysed the scripting well enough to be sure that is the correct directory when pre-downloading, or that that is the correct way of doing so.
The scripting does check the integrity of the download, so one possibility it that a failed download wasn’t overwritten by the second attempt (a .2 or .3 version was created, instead), and simply removing the failed download and running configure may be enough.
Generally, this part of the process should work, as long as your have good connectivity and the file server is working a the time, so people generally won’t have experience of having to fix things up manually.