Esp8266 or 32 - ws2815 connction for blynk

How can ı connect esp32/8266 with ws2815. I dıdınt see anything for this connection.

The WS2815 is an LED strip, not a Blynk connection method.
With the ESP8266 or ESP32 the connection method to select will be WiFi.

The WS2815 strips are designed to work with 5v logic level, and the ESP range of MCUs use 3.3v logic levels. You may get the strips to work as desired at 3.3v, but a logic level shifter may be required.
As far as code is concerned, there are a variety of projects on the forum which use the FastLED library, and you should take a look at these for inspiration.