There are two ways to apply for a provincial nomination in the Express Entry process:
(Passive Approach) You create an Express Entry profile and indicate that you are interested in a particular province or territory.
(Proactive Approach) You contact a province or territory directly and apply to be nominated under an Express Entry stream.
Let's explore both of these options in greater detail:
Passive. A province or territory finds your Express Entry profile and contacts you
In this case, provinces and territories use the portal to search for candidates in the Express Entry pool.
They can narrow their search by filtering profiles for factors such as language ability, education, work experience, etc.
Provinces and territories can find your profile if you:
You will only have 30 days to accept or reject the nomination.
You may be nominated by more than one province at a time, but you can only accept one nomination at a time.
Proactive. Apply to a province or territory directly
In this case, you are applying directly to the province or territory for nomination.
You must meet the eligibility requirements of one of their Express Entry-aligned streams and apply to the province directly on their official website.
If they are interested in nominating you, you then:
From there, simply click the "accept" or "not accept" button in your account.
The two approaches are very similar and both require you to have an Express Entry profile.
The paper-based PNP approach is unrelated to Express Entry.
In this case, you are applying directly to the province or territory under a non-Express Entry-aligned stream.
You must meet the eligibility requirements of a non-Express Entry-aligned PNP and apply to the province directly on their official website.

You can receive more than one notification of interest at a time, but can only have one nomination at a time. If you received an offer for nomination from one province or territory, but would like to be selected by a different province or territory, you have to decline the first nomination before another province can send you their nomination.