What are nulled items, and why WP Contact Us Form by Elfsight here is the right choice?

All “nulled” means is that the item is preactivated and ready to be used the moment you install it. License notices, if any appear, can simply be ignored — they change nothing about how WP Contact Us Form by Elfsight runs. License keys are only ever required for support from the original author, which is of course not included here.

Every item advertised on our site is 100% safe. Each file is tested and verified by three separate anti-virus and anti-malware programs before it is ever listed, and re-checked on every new version we publish.

• Preactivated on install — nothing to enter, nothing to configure
• Original developer files, unmodified and complete
• Scanned by three anti-virus and anti-malware tools
• Distributed under the GPL, the licence WordPress itself uses