Issue with Celestial Warlock "Radiant Soul" Class Feature

Would it be Possible to fix "Radiant Soul" for single target spells if auto adds the charisma modifier. Such as for "Sacred Flame". As when I roll it is not adding in my +5 Charisma Modifier.

The problem with that is the Radiant Soul feature only applies that damage to one roll against one target. So if you used your Wall of Fire all creatures would take normally rolled damage - and one creature would take an extra 5. If DNDBeyond included it - all the creatures you hit would take the extra 5. Not to mention that it also only applies to fire and radiant spells.

It's simply too irregular to properly take account of in the dice roller.