[SDPhantom]

You can try this. Be sure to add frame:EnableMouse(true) up where the frame is being set up to have it respond to mouse events.

frame:SetScript("OnEvent", function(self, event, ...)
    local itemID, _, itemName, itemIcon, totalXP, pointsSpent = C_ArtifactUI.GetEquippedArtifactInfo()
 
    if itemID then
        local pointsFree, xpToNextPoint = 0, C_ArtifactUI.GetCostForPointAtRank(pointsSpent);
 
        while totalXP >= xpToNextPoint do
            totalXP, pointsSpent, pointsFree, xpToNextPoint = totalXP - xpToNextPoint, pointsSpent + 1, pointsFree + 1, C_ArtifactUI.GetCostForPointAtRank(pointsSpent + 1);
        end
        text:SetFormattedText("AP |cff00ff00%d/%d (%.1f%%)|r" .. (pointsFree > 0 and " (+%d)" or ""), totalXP, xpToNextPoint, 100 * totalXP / xpToNextPoint, pointsFree);
    end
 
    frame:SetShown(itemID and true or false);
end);
 
frame:SetScript("OnEnter", function(self)
    local _, _, itemName = C_ArtifactUI.GetEquippedArtifactInfo()
    local _, akLevel = GetCurrencyInfo(1171);
 
    GameTooltip:SetOwner(self, "ANCHOR_BOTTOM");
    GameTooltip:SetText(itemName);
    if akLevel > 0 then
        GameTooltip:AddLine(string.format("Artifact Knowledge |cff00ff00%d (+%d%%)|r",akLevel,akMulti[akLevel] or 0));
    end
    GameTooltip:Show();
end);
 
frame:SetScript("OnLeave", function(self) GameTooltip:Hide(); end);