I do it the following way,
Step 1 - Use make.com to integrate calendly with airtable
Step 2 - Connect airtable with airscale.io, or clay/apollo.io enricher to scrape the details.
Step 3 - Find additional information about the company/people using apify/texau website scraper. I do it manually. (If needed)
Step 4 - Use Open AI Platform/Airtable AI to generate meeting prep notes based on input from descriptions. (If needed)
You can connect airtable directly with slack.