I'll show you the right way.
In order to receive monero anonymously, if you purchase from an exchange accompanied by KYC and transfer it to the Dark-web market, it is a stupid act to use the exchange with KYC because the address is adsorbed with KYC inside the Dark-web market address
Even if you do it, it is recommended to transfer it one step after receiving the transfer to use a clean wallet address while using the Monero encryption technology called Ring signature
It is recommended that you use a platform that exchanges Bitcoin to Monero using Monero Pool in a Dex exchange or make transactions through OTC trading.
Digital security is always up to you, and I recommend you to do a simple YouTube or research for Ring signature technology.