Rename the file finatra-kafka-streams-queryable-thrift-client_2.12-22.3.0-javadoc.jar to finatra-kafka-streams-queryable-thrift-client_2.12-22.3.0-javadoc.zip
Use your favourite unzip tool (WinRAR / WinZIP) to extract it, now you have a folder finatra-kafka-streams-queryable-thrift-client_2.12-22.3.0-javadoc
Double click index.html will open the index page on your default web browser.