BME280 and altitude , wrong reading

Since a few days I build an AirRohr with the NodeMCU and included a BME280 sensor
Everything is working fine, just I discover that the BME280 sensor is reading “low” pressure…
I’m living at 210m of altitude and want to know how can I adjust the value for SEALEVELPRESSURE_HPA

Is there a possibility to adjust my location above sealevel?


Maybe this is useful:

It is already here:

hoi Jan
bedankt voor de info