I checked the FAQ and they said, I will get a code after the first mix. And later mentioned using that code. I still don't understand this matter basically how I can get that code.
https://www.talkimg.com/images/2023/07/14/ZVqV1.png
After inputting the receiving address then, proceed by clicking Create order. Then, Your Mixing Order page will appear, where you will get the Mixing Code that you can save and use again for the next transaction.
In other BTC mixing services I have used, I think the Mixing Code functions in /]Yo!Mix similarly to the Session Token in CM.
I have already managed to mix my BTC through this yomix! service. And I save the code that I get from there, so that I can use that code in future transactions. Thank you very much for helping me understand these Yomix! services.