Sentinel and data collection

Hi, I have Turris OS 4.0.1 hbs on a metal-colored Omnia. I tried to install sentinel-nikola and sentinel-minipot following this guide: https://docs.turris.cz/basics/collect/
But after executing the installation command, I get a couple of errors. Can anyone help me understand?

root@turris:~# opkg install sentinel-nikola sentinel-minipot
Installing sentinel-nikola (2.0-3.6-1.16) to root…
Downloading https://repo.turris.cz/hbs/omnia/packages/turrispackages/sentinel-nikola_2.0-3.6-1_arm_cortex-a9_vfpv3.ipk
Installing libgpg-error (1.12-1.1) to root…
Downloading https://repo.turris.cz/hbs/omnia/packages/packages/libgpg-error_1.12-1_arm_cortex-a9_vfpv3.ipk
Installing libgcrypt (1.6.6-3.0) to root…
Downloading https://repo.turris.cz/hbs/omnia/packages/packages/libgcrypt_1.6.6-3_arm_cortex-a9_vfpv3.ipk
Installing libmicrohttpd (0.9.59-1.1) to root…
Downloading https://repo.turris.cz/hbs/omnia/packages/packages/libmicrohttpd_0.9.59-1_arm_cortex-a9_vfpv3.ipk
Installing liblz4 (v1.7.5-1.1) to root…
Downloading https://repo.turris.cz/hbs/omnia/packages/packages/liblz4_v1.7.5-1_arm_cortex-a9_vfpv3.ipk
Installing czmq (4.2.0-2.0) to root…
Downloading https://repo.turris.cz/hbs/omnia/packages/packages/czmq_4.2.0-2_arm_cortex-a9_vfpv3.ipk
Installing libpaho-mqtt-c (1.3.0-1.17) to root…
Downloading https://repo.turris.cz/hbs/omnia/packages/turrispackages/libpaho-mqtt-c_1.3.0-1_arm_cortex-a9_vfpv3.ipk
Installing sentinel-proxy (1.1-5.2) to root…
Downloading https://repo.turris.cz/hbs/omnia/packages/turrispackages/sentinel-proxy_1.1-5_arm_cortex-a9_vfpv3.ipk
Configuring libgpg-error.
Configuring libgcrypt.
Configuring libmicrohttpd.
Configuring liblz4.
Configuring czmq.
Configuring libpaho-mqtt-c.
Configuring sentinel-proxy.
Command failed: Not found
Configuring sentinel-nikola.
Reloading syslog-ng
Installing sentinel-minipot (1-6.16) to root…
Downloading https://repo.turris.cz/hbs/omnia/packages/turrispackages/sentinel-minipot_1-6_arm_cortex-a9_vfpv3.ipk
Installing msgpack-c (2.1.5-2.0) to root…
Downloading https://repo.turris.cz/hbs/omnia/packages/turrispackages/msgpack-c_2.1.5-2_arm_cortex-a9_vfpv3.ipk
Configuring msgpack-c.
Configuring sentinel-minipot.
Command failed: Not found
Bad argument 192.168.100.1:2333' Tryiptables -h’ or ‘iptables --help’ for more information.
iptables: No chain/target/match by that name.
/tmp/sentinel-remove-iptables: line 2: 192.168.100.1:2333: not found
Bad argument 192.168.100.1:2333' Tryiptables -h’ or ‘iptables --help’ for more information.

If I try to connect to the public IP address given to me by the operator, I receive this answer:
Trying xxx.xxx.xxx.xxx…
telnet: Unable to connect to remote host: Connection refused