[PAGE ISSUE] Lazy minting, npm run test error

[Quantmatic]

https://github.com/protocol/nft-website/blob/main/docs/tutorial/lazy-minting.md

steps to replicate:
git clone https://github.com/ipfs-shipyard/nft-school-examples
cd nft-school-examples/lazy-minting
npm install
npm run test

$ npx hardhat test
Compiling 16 files with 0.8.4
Compilation finished successfully


  LazyNFT
    ✓ Should deploy (758ms)
    ✓ Should redeem an NFT from a signed voucher (190ms)
    ✓ Should fail to redeem an NFT that's already been claimed (162ms)
    ✓ Should fail to redeem an NFT voucher that's signed by an unauthorized account (109ms)
    ✓ Should fail to redeem an NFT voucher that's been modified (122ms)
    ✓ Should fail to redeem an NFT voucher with an invalid signature (91ms)
    ✓ Should redeem if payment is >= minPrice (87ms)
    ✓ Should fail to redeem if payment is < minPrice (69ms)
    1) Should make payments available to minter for withdrawal


  8 passing (2s)
  1 failing

  1) LazyNFT
       Should make payments available to minter for withdrawal:
     TypeError: account.getAddress is not a function
      at Object.getAddressOf (node_modules/@ethereum-waffle/chai/dist/cjs/matchers/misc/account.js:14:24)