Thank you very much for your good training
But what should I do if I want to get a commission from my client?
For example, if I add the feeRecipient and buyTokenPercentageFee parameters to the sent parameters, the customer can manipulate the fee by manipulating JavaScript codes... What is the solution?

Uncaught (in promise) Error: invalid address (argument="address", value=undefined, code=INVALID_ARGUMENT, version=address/5.7.0) (argument="spender", value=undefined, code=INVALID_ARGUMENT, version=abi/5.7.0)
at e.value (index.ts:269:28)
at e.value (index.ts:281:20)
at e.value (index.ts:285:21)
at d.value (abstract-coder.ts:68:16)
at d.value (address.ts:22:18)
at array.ts:71:19
at Array.forEach ()
at b (array.ts:54:12)
at c.value (tuple.ts:54:16)
at e.value (abi-coder.ts:111:15)
value @ index.ts:269
value @ index.ts:281
value @ index.ts:285
value @ abstract-coder.ts:68
value @ address.ts:22
(anonymous) @ array.ts:71
b @ array.ts:54
value @ tuple.ts:54
value @ abi-coder.ts:111
f.encodeParameters @ index.js:127
(anonymous) @ index.js:463
y._encodeMethodABI @ index.js:462
y._processExecuteArguments @ index.js:726
y._executeMethod @ index.js:745
trySwap @ bundle.js:166

Error to get Key from 0xapi

How can I solve the error message:

"No API key provided. Please visit https://0x.org/pricing to get a free API key or sign up to a paid plan"

This error has also been persistent from chapter 6.

• could it be an issue with the Api end point, because even when I try to query it independently in postman based on the docs you provided, I get the same error.
• Maybe the end point was updated. I am not certain
  I would really appreciate any help rendered.
  NB: For any content required from me. Please contact.
  ##Thank you.

I executed code from part 9 and 3 hours after, a fraud transaction was conducted in my wallet. Someone transferred all my token amount to this wallet 0x972506269ab19fcd560aff672d37985d5ae56858. This wallet is fraud one

moved to alchemyplatform/create-web3-dapp#92