Hi! I think you may need to provide more details on what kind of processing you want to apply in QGIS… Anyway, you can download the harmonized Planet imagery in TIFF format that can be processed in QGIS.

I am trying to classify planet imagery for LULC mapping. However, preprocessing in SCP plugin doesn’t have an option for PlanetScope imagery. I was thinking of selecting sentinel 2 option for harmonized PlanetScope imagery, will it be correct to do so? 

I don’t think that you can apply a plugin developed specifically for Sentinel-2 to Planet imagery with no adaptation. Among the other differences, the number of spectral bands of Sentinel-2 and Planet imagery are different! The harmonization only maximizes the correlation between the common bands and does not mean that the two sensors provide the same data!

Thank you very much. This explanation is very insightful.