It's important to differentiate between:
NDIS (National Disability Insurance Scheme): This is the Australian government scheme that provides funding for people with disability.1
NDP (National Disability Practitioners): This is a professional body for people working in the disability sector.2 It provides resources, training, and support to disability practitioners.3
Therefore, you "apply for NDIS support" to the NDIS, and NDP can support you in ways regarding your NDIS plan management, and providing resources to people working within the NDIS system.4Here's a breakdown:Applying for NDIS Support:
To apply for NDIS support, you need to meet the NDIS eligibility criteria.
The primary source of information and the place to start your application is the official NDIS website:

ndis.gov.au

On the NDIS website, you'll find information about:

Eligibility requirements.
The application process.
The types of supports funded by the NDIS.

How NDP Relates to NDIS:
NDP plays a role in supporting the disability workforce, which in turn supports NDIS participants.5
NDP also provides NDIS plan management. This is where they can help you to manage the funds within your NDIS plan.
Therefore, NDP can help you manage your NDIS plan, but you apply to the NDIA to become a NDIS participant.6
Key Points:
Visit the official NDIS website (ndis.gov.au) for accurate and up-to-date information on applying for NDIS support.7
NDP can provide valuable resources and support, especially regarding plan management.
I hope this helps.