Zapier's free plan is basically useless for this. You get 100 tasks a month and only single step zaps, so pulling a lead from Facebook, pushing it to your CRM, and sending an email notification already eats 3 tasks per lead. Twenty or thirty leads and you're capped.
What I've actually used or looked at as alternatives:
Meta's own tools first - before reaching for any third party app, connect your CRM directly through Meta's native integrations if it supports one. HubSpot, Mailchimp, and a few others plug straight into Facebook and Instagram lead forms without needing Zapier at all. This is the cheapest and most reliable path if your CRM is on that list.
Pabbly Connect - this is the one I'd point people to first. It has a genuinely usable free tier, supports way more steps per workflow than Zapier's free plan, and connects Facebook lead ads to most CRMs and email tools without much fuss.
LeadsBridge - built specifically for ad platform to CRM syncing rather than general automation. It's an official Meta Business Partner and specializes in marketing and advertising workflows. The free tier is limited but the paid entry plan is cheap and does exactly this one job well, syncing Facebook, Instagram, and other Meta lead sources straight into your CRM or email tool in real time.
LeadSync - similar niche play. It focuses on real time syncing from Meta, Google, LinkedIn and TikTok lead forms into over 30 CRMs, and gets around the polling delay that Zapier has where a lead can sit for up to 15 minutes before it even lands in your system.
n8n - if you or someone on your team is comfortable with a bit of technical setup, this is the strongest fully free option. You self host it, which means no task limits at all, and it can handle Facebook and Instagram webhooks into any CRM or email service you want. Takes longer to set up than the plug and play tools but once it's running you're not paying anyone a monthly fee.
Make (formerly Integromat) - more generous free tier than Zapier, visual workflow builder, and handles Facebook lead ad triggers well. Good middle ground if n8n feels too technical but you still want more room than Zapier gives you.
My honest take: if you're only dealing with Facebook and Instagram lead ads and nothing else, skip general automation tools entirely and go with something purpose built like Pabbly or LeadsBridge. Save Zapier or Make for when you need to connect a dozen different apps across your whole business, not just lead capture.