You haven’t answered the questions asked of you:
And there are many hits on Google for “Heltec V3 I2C BME280” with links to the Heltec forum, a GitHub repro, a YouTube video, the Meshtasic forum (x2) and the Arduino forum which has a link to a pretty reasonable blog that says how to do it.
Point 1 being the strongest here, I can see how you are likely to be using LW given this module but some confirmation would be good because, as above, this is a forum for TTN, not a forum for Heltec, we have to stay focused. Even if you are using TTN, then this question is somewhat marginal as it’s more of a Heltec V3 / ESP32 / how to read the data sheet & schematic type thing for a device.
And you haven’t posted on the Heltec forum as recommended where we are free to discuss all & everything related to Heltec products without needing the context of LoRaWAN on TTN/TTI.