Charged Based on Proficiency

[DeathSheep]

I am trying to set up an attack, similar to Dragonborn breath weapon attacks, but the number of uses is equal to your proficiency bonus. I thought I had it set up correctly, but the charges don't show up in play. What is the right syntax to get this to work?

Here is the current code:

  <thing id="raPRSonicScream" name="Sonic Scream" description="As an action, you can violently expel air in a 15-foot cone. When you do so, each creature in the area of the exhalation must make a Wisdom saving throw (DC = 8 + your proficiency bonus + your Constitution modifier). A creature takes 2d6 sonic damage on a failed save, and half as much damage on a successful one. The damage increases to 4d6 at 5th level, 6d6 at 11th level, and 8d6 at 17th level. This ability has no effect on constructs. You can use this feature a number of times equal to your proficiency bonus. You regain all expended uses when you complete a long rest." compset="RaceSpec">
    <fieldval field="abValue2" value="6"/>
    <fieldval field="trkMax" value="hero.childfound[ProfBonus].field[tProfBonus].value"/>
    <tag group="StandardDC" tag="aCON" name="Constitution" abbrev="Constitution"/>
    <tag group="Usage" tag="LongRest"/>
    <tag group="User" tag="Tracker" name="tracker" abbrev="tracker"/>
    <tag group="Helper" tag="ShowSpec" name="Show Spec" abbrev="Show Spec"/>
    <tag group="LvNamePar" tag="AppText" name="Append &quot;field[abText].text&quot;" abbrev="Append &quot;field[abText].text&quot;"/>
    <tag group="DamageType" tag="dtPRSonic" name="sonic" abbrev="sonic"/>
    <tag group="abSave" tag="aWIS"/>
    <tag group="Helper" tag="NoAttrDam"/>
    <eval phase="PostAttr" priority="10000"><![CDATA[
      if (#totallevelcount[] >= 16) then
        field[abValue].value += 5
      elseif (#totallevelcount[] >= 11) then
        field[abValue].value += 4
      elseif (#totallevelcount[] >= 6) then
        field[abValue].value += 3
      else
        field[abValue].value += 2
        endif

      perform root.pulltags[DamageType.?]]]></eval>
    <eval phase="Final" priority="10000" index="2"><![CDATA[
      ~need to put the damage up front
      field[abText].text = field[abValue].value & "d" & field[abValue2].value & " " & tagnames[DamageType.?] & ", " & field[abText].text]]></eval>
    </thing>