Unable to find some nodes - PDF Parser & Tika Parser

Hello everyone,

I am a newcomer to Knime, have been just recently using the platform.

I am using the version KNIME 5.4.3 right now, but unfortunately I can not find some of the nodes when I search it on my app. For example, I need to work on PDF documents and as I explored some stuff, there are nodes called “PDF Parser” and “Tika Parser” which can be helpful. Could you help me why I can not find this node on my application?

Thank you.