TL;DR: Multiple phases can be done by editing an Edition Page for each of the phases with your desired requirements.
How it works
Let's say you're looking to setup a claim with 3 different phases.
Phase 1: Allowlist for a small group of addresses for free
Phase 2: A larger allowlist with a discounted cost
Phase 3: Open to public with original cost
How you would set this up:
Publish an Edition Page with the first allowlist and the price set to free.
Once Phase 1 is complete, edit the existing Edition Page with the new allowlist and change to your desired cost, then publish.
Once Phase 2 is complete, edit the existing Edition Page and remove the allowlist requirement, then update to your new desired cost and publish again.
Please note multiple phases cannot be active at the same time.
Want to try it out first? Use your Testnet Workspace to demo before launching.