C_UnitAuras.GetAuraDataByIndex()

If any addon writers here, I want to see the tick values of various debuffs/DoTs, just as they are displayed on the tooltips on nameplates. For example “Bleed” which ticks for 1000 every 2 seconds (example, hypothetical DoT).

I can read the auras (debuffs) with C_UnitAuras.GetAuraDataByIndex() but the return structure does not always show the tick values - some I can see and some I cannot.

If anyone knows how to interpret the return structure better than I can, or any other API call that can give me the information?

You need to use C_TooltipInfo.GetUnitAura which returns tooltip text and then parse this tooltip.