Agapeyoga wrote

I created one network. How can I create a 4g and a 6 g network 

If you want to split your bands, you need to disable Smart Connect in the wireless settings. That'll let you name your 2.4GHz, 5GHz, and 6GHz networks separately.

Since you're on WiFi 6E, check these guides for managing the 4GHz and 6GHz bands:

https://www.tp-link.com/us/support/faq/4343/ 

https://community.tp-link.com/en/home/forum/topic/648672