How to dynamically read numbers for `limit` operator in $:/config/EmptyStoryMessage

Doesn’t $:/config/EmptyStoryMessage file support using variables, I tried it but it doesn’t seem to work, I’m making a load more button at the bottom of the story river, example

<!-- use variable, but not work -->
<$set name="a-count" value="{{!!a-count}}">
<!-- some code -->
</$set>
<!-- use global macro -->
title: $:/config/EmptyStoryMessage

{{{ [[GettingStarted]] ||$:/core/ui/ViewTemplate }}}
{{{ [!is[system]field:publish[article]!sort[modified]limit<a-count>] -[[GettingStarted]]||$:/core/ui/ViewTemplate}}}

<!-- status -->
<$list filter="[[$:/state/a-count]is[missing]]">
<center>
	<$button class="o-load-more" set="$:/state/a-count" setTo="yes">
    &nbsp;
     <svg stroke="currentColor" fill="currentColor" stroke-width="0" viewBox="0 0 16 16" height="1em" width="1em" xmlns="http://www.w3.org/2000/svg"><path d="M3 9.5a1.5 1.5 0 1 1 0-3 1.5 1.5 0 0 1 0 3zm5 0a1.5 1.5 0 1 1 0-3 1.5 1.5 0 0 1 0 3zm5 0a1.5 1.5 0 1 1 0-3 1.5 1.5 0 0 1 0 3z"></path></svg>
    &nbsp;
    <$action-setfield $tiddler="$:/temp/a-count" text="\define a-count() 10" tags="$:/tags/Macro"/>
	</$button>
</center>
</$list>

Keep in mind there is no current tiddler set in the emptyStory, so in your example {{!!a-count}} is getting a field value from the currentTiddler that is not set.

Use the tiddler widget, or also set currentTiddler variable first, such as to $:/config/EmptyStoryMessage or as appropriate.

:tada: It seems to be working fine now

{{{ [[GettingStarted]] ||$:/core/ui/ViewTemplate }}}
<$set name="a-count" value={{{ [[$:/temp/articles/number]get[number]] }}}>
{{{ [!is[system]field:publish[article]!sort[modified]limit<a-count>] -[[GettingStarted]]||$:/core/ui/ViewTemplate}}}
</$set>

<$set name="a-total" value={{{ [field:publish[article]count[]] }}}>
<$set name="a-num" value={{{ [[$:/temp/articles/number]get[number]else[0]add[1]] }}}>
<$list filter="[<a-num>compare:number:lteq<a-total>]">
<center>
	<$button class="o-load-more" tooltip="Load rencent articles">
    &nbsp;
     <svg stroke="currentColor" fill="currentColor" stroke-width="0" viewBox="0 0 16 16" height="1em" width="1em" xmlns="http://www.w3.org/2000/svg"><path d="M3 9.5a1.5 1.5 0 1 1 0-3 1.5 1.5 0 0 1 0 3zm5 0a1.5 1.5 0 1 1 0-3 1.5 1.5 0 0 1 0 3zm5 0a1.5 1.5 0 1 1 0-3 1.5 1.5 0 0 1 0 3z"></path></svg>
    &nbsp;
  <$action-setfield $tiddler="$:/temp/articles/number" number={{{ [<a-num>] }}}/>
	</$button>
</center>
</$list>
</$set>
</$set>