Question regarding the free DNS option

hi, i am new to Cloudflare. Looking for a new place to host our DNS accounts and so am trying this out. Have set up a couple of accounts that seem to work ok on the free plan (without the proxy).
My question is, are we required to have some sort of paid plan with Cloudflare in order to continue using the free DNS option? is there a term that states that the account gets shut down after a period of time if we don’t have paid set up?
I’m still testing all of this out at the moment so not looking to commit to paid DNS just yet, and I don’t want any surprises.

thanks

Cloudflare offers a completely free tier, this is not a trial and doesn’t expire.

thank you thedaveCA for your reply.