user128959: I configured the I2P according to this answer on Ubuntu 20.04 and 21.10.
But I have been getting the following error when I try to connect to any I2P peer:
I2P: Error connecting to a5qsnv3maw77mlmmzlcglu6twje6ttctd3fhpbfwcbpmewx6fczq.b32.i2p:0: Receive timeout (received 0 bytes without terminator before that)

This error occurs for any peer, not just the above.
How can I find the reason for this error and fix it?

UPDATE: Adding information requested by Prayank.
$ sudo ufw status verbose
Status: inactive

$ ss -nlt
State                Recv-Q               Send-Q                               Local Address:Port                                Peer Address:Port               Process               
LISTEN               0                    128                                      127.0.0.1:7656                                     0.0.0.0:*       
...


UPDATE 2: I was able to reach the website git.idk.i2p using the steps described in http://geti2p.net/en/about/browser-config .

UPDATE 3: Results of executing the steps: https://github.com/vasild/bitcoin/pull/4
$ telnet 127.0.0.1 7656
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
HELLO VERSION MIN=3.1 MAX=3.1
HELLO REPLY RESULT=OK VERSION=3.1
SESSION CREATE STYLE=STREAM ID=mysession1 DESTINATION=TRANSIENT SIGNATURE_TYPE=7
<no-response>

According to the text, a response (SESSION STATUS RESULT=OK) was expected. This didn't happen. No response was received.
Result of the other test.
$ telnet 127.0.0.1 7656
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
HELLO VERSION MIN=3.1 MAX=3.1
HELLO REPLY RESULT=OK VERSION=3.1
NAMING LOOKUP NAME=git.idk.i2p
NAMING REPLY RESULT=OK NAME=ME VALUE=80...AAA==
STREAM CONNECT ID=mysession1 DESTINATION=80...AAA== SILENT=false
STREAM STATUS RESULT=CANT_REACH_PEER

Received CANT_REACH_PEER instead of STREAM STATUS RESULT=OK.

user128959: I was able to fix this issue by going to http://127.0.0.1:7657/configclients in the browser and enabling "SAM application bridge".
This was disabled by default.

user129003: Can you reach anything over I2P? For example, can you browse http://git.idk.i2p/ using the router's http proxy?

128959: <p>I configured the I2P according to this <a href="https://bitcoin.stackexchange.com/a/103403/128959">answer</a> on Ubuntu 20.04 and 21.10.</p>
<p>But I have been getting the following error when I try to connect to any I2P peer:</p>
<pre><code>I2P: Error connecting to a5qsnv3maw77mlmmzlcglu6twje6ttctd3fhpbfwcbpmewx6fczq.b32.i2p:0: Receive timeout (received 0 bytes without terminator before that)
</code></pre>
<p>This error occurs for any peer, not just the above.</p>
<p>How can I find the reason for this error and fix it?</p>
<hr />
<p>UPDATE: Adding information requested by <a href="https://bitcoin.stackexchange.com/users/103136/prayank">Prayank</a>.</p>
<pre><code>$ sudo ufw status verbose
Status: inactive
</code></pre>
<pre><code>$ ss -nlt
State                Recv-Q               Send-Q                               Local Address:Port                                Peer Address:Port               Process               
LISTEN               0                    128                                      127.0.0.1:7656                                     0.0.0.0:*       
...
</code></pre>
<hr />
<p>UPDATE 2: I was able to reach the website git.idk.i2p using the steps described in <a href="http://geti2p.net/en/about/browser-config" rel="nofollow noreferrer">http://geti2p.net/en/about/browser-config</a> .</p>
<hr />
<p>UPDATE 3: Results of executing the steps: <a href="https://github.com/vasild/bitcoin/pull/4" rel="nofollow noreferrer">https://github.com/vasild/bitcoin/pull/4</a></p>
<pre><code>$ telnet 127.0.0.1 7656
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
HELLO VERSION MIN=3.1 MAX=3.1
HELLO REPLY RESULT=OK VERSION=3.1
SESSION CREATE STYLE=STREAM ID=mysession1 DESTINATION=TRANSIENT SIGNATURE_TYPE=7
&lt;no-response&gt;
</code></pre>
<p>According to the text, a response (SESSION STATUS RESULT=OK) was expected. This didn't happen. No response was received.</p>
<p>Result of the other test.</p>
<pre><code>$ telnet 127.0.0.1 7656
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
HELLO VERSION MIN=3.1 MAX=3.1
HELLO REPLY RESULT=OK VERSION=3.1
NAMING LOOKUP NAME=git.idk.i2p
NAMING REPLY RESULT=OK NAME=ME VALUE=80...AAA==
STREAM CONNECT ID=mysession1 DESTINATION=80...AAA== SILENT=false
STREAM STATUS RESULT=CANT_REACH_PEER
</code></pre>
<p>Received <code>CANT_REACH_PEER</code> instead of <code>STREAM STATUS RESULT=OK</code>.</p>
 128959: <p>I was able to fix this issue by going to <a href="http://127.0.0.1:7657/configclients" rel="nofollow noreferrer">http://127.0.0.1:7657/configclients</a> in the browser and enabling &quot;SAM application bridge&quot;.</p>
<p>This was disabled by default.</p>
 129003: <p>Can you reach anything over I2P? For example, can you browse <a href="http://git.idk.i2p/" rel="nofollow noreferrer">http://git.idk.i2p/</a> using the router's http proxy?</p>
