I just created a droplet Debian 9.27 (64 bit).
Logged in as root and followed the confluence install page: https://freeswitch.org/confluence/display/FREESWITCH/Debian+8+Jessie
Which fails:
root@debian-fs-test:~# wget -O - https://files.freeswitch.org/repo/deb/freeswitch-1.8/fsstretch-archive-keyring.asc | apt-key add -
--2019-05-28 18:09:13-- https://files.freeswitch.org/repo/deb/freeswitch-1.8/fsstretch-archive-keyring.asc
Resolving files.freeswitch.org (files.freeswitch.org)... 190.102.98.174, 2803:d000:fffe::174
Connecting to files.freeswitch.org (files.freeswitch.org)|190.102.98.174|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 3155 (3.1K) [text/plain]
Saving to: ‘STDOUT’
- 100%[===========================================================================================================>] 3.08K --.-KB/s in 0s
2019-05-28 18:09:13 (71.7 MB/s) - written to stdout [3155/3155]
OK
root@debian-fs-test:~# echo "deb http://files.freeswitch.org/repo/deb/freeswitch-1.8/ jessie main" > /etc/apt/sources.list.d/freeswitch.list
root@debian-fs-test:~# echo "deb-src http://files.freeswitch.org/repo/deb/freeswitch-1.8/ jessie main" >> /etc/apt/sources.list.d/freeswitch.list