Susceptibility correction using fieldmaps

Dear all,
I am completely new to DWI preprocessing and I would love to know that fieldmaps can finally be used instead of opposite phase-encoding-direction images for bias field correction in the current MRtrix version. I saw older posts about this possibility but can’t determine whether it has now been implemented or not (it seems to be that it’s still not there, but asking just in case I’m wrong).
e.g. Request: Field map correction in preproc scripts
e.g. Inhomogeneity field estimation without reverse phase
thanks in advance for any further help!
alessandra