You have (at least) two options:
- go into Engrave/Music Symbols/Dynamics and see if there are preconfigured entries you’re sure you won’t ever need. You can then modify/replace those. This will retain placement rules for dynamics.
- go into Engrave/Playing techniques… and create whatever you wish. Set the font range to Dynamics and you have the building blocks you need. Dynamics created this way will have to be manually positioned in Engrave mode
