ESP-01 Tasmota ambient sensor (BME280): A detailed project describing how to build the sensor and then integrate with HASS (link in the comments) : r/homeassistant
Push sensor data to luftdaten.info aka sensor.community using Tasmota and openHAB - Solutions - openHAB Community
BME280 temperature, humidity and pressure sensor - Tasmota
Testing some I2C sensors with ESP01 and Tasmota | Hydrosys4