Do I need an Apollo paid plan to use NioLeads?

NioLeads is not limited to the Apollo scraper, so having an Apollo subscription is not mandatory.

If you do want to scrape emails from Apollo however, it is recommended to have a paid subscription to get access to the full Apollo database.

Technically speaking you can use NioLeads with the free plan of Apollo, but you will get limited to only the first 100 leads available in a search - which is usually not enough.