Hi @ttaleei, if you are a new Brainstorm user, we recommend you start by following the introduction tutorials first (section "Get started" on the tutorial page), using the example dataset that is provided.
https://neuroimage.usc.edu/brainstorm/Tutorials
This is described in detail in the source estimation tutorial (part of the suggested series):
https://neuroimage.usc.edu/brainstorm/Tutorials/SourceEstimation
For the moment only sLORETA is implemented in Brainstorm. Check this discussion:
Loreta and Source localization - #5 by Sylvain