Purple checkmarks are for Farcaster users who have set their profile photo (pfp) to an NFT in a connected Ethereum address. To do this:
Connect an Ethereum address with NFTs in it — if you did that at sign up you should be all set, if you need to connect another Ethereum address, it’s available in Settings > Connect Address. Note: we currently only support Ethereum L1 NFTs and don’t support Gnosis safes
After connecting your address, it may take a few minutes to index all of the NFTs. Grab a beverage, browse a few Farcaster profiles, cast a meme, etc.
Go to your Farcaster profile and then click on the NFTs tab. You’ll have to scroll through your NFTs for now (search coming soon). Click on the NFT and then click the Set as pfp button.