the FBs MC_BR_ProcessConfig as well as MC_BR_ProcessParam can not cover this use-case of changing the MpAlarmXConfiguration of a mappMotion axis component.
But in the mappAlarmX documentation I have found some quidance which could help you with that:
Please check following path in AS help: B&R Online Help
Under point “Configuring mapp Motion alarms“ it is explained how such alarms for an axis can be configured/adjusted: