Appian not detecting custom plugin

Hi I am having trouble deploying a custom-built plugin. I have followed appian documentation about creating plugins and still appian isn't detecting it. I use eclipse to develop and have installed the appian eclipse plugin to create appian java projects. The plugin contains a simple function that returns a string "Hello World". Please help!!

This is the documentation I followed to create my plugin: https://docs.appian.com/suite/help/17.2/Custom_Function_Plug-ins.html

Am I missing something crucial for it to work? Is there a way to see where the plugin is failing?

My appian plugin xml

<appian-plugin name="Document 64 Plugin" key="appian.plexus.document64plugin">

<plugin-info>
<description>Document 64 Plugin</description>
<vendor name="Example" url="http://www.google.com" />
<version>1.0.0</version>
<application-version min="6.1.0" />
</plugin-info>

<!--<function key="encodeDocument64" class="com.appian.plexus.document64.documentToBase64"/>-->

<function-category key="appianPlexusDocument64Category" name="appianPlexusDocument64"/>
<function key="HelloWorld64" class="com.appian.plexus.document64.DocumentHelloWorld64"/>

</appian-plugin>

Here is my class

package com.appian.plexus.document64;

import org.apache.log4j.Logger;

import com.appiancorp.services.ServiceContext;
import com.appiancorp.suiteapi.expression.annotations.Function;
import com.appiancorp.suiteapi.expression.annotations.Parameter;

@AppianPlexusDocument64Category
public class DocumentHelloWorld64 {

private static final Logger LOG = Logger.getLogger(DocumentHelloWorld64.class);

@Function
public String HelloWorld64(ServiceContext sc, @Parameter String word) {
return "Hello World";
}

}