Cannot insert variables into Tooltip.

[smokiebacon]

data-tooltip only allows strings. I need to put in variables, such as timestamp created. Even using template literals will not work, such as:
data-tooltip='${variableHere}'

Won't work without parenthesis.
data-tooltip=variable. will not work.

will not work:
data-tooltip="{{comment.created | dateFormat("dddd, MMMM Do YYYY, h:mm:ss a")}}" . (using Vue)

Anyone figure out how to drop variables?