Set filter with Javascript (need help on submit)

We need to code a way to set a hidden filter field with the username (stored in a variable)

I know isnt something really supported by the plugin by default but we did manage to hide (css) and fill (javascript) the field with the variable content already (it has a invalid default value so it shows nothing when loaded)

The code we have almost working for now is:

<script type=”text/javascript”>
var userid = “<?php echo do_shortcode(‘[prflxtrflds_field field_id=1]’);?>”;
function filluser() {
document.querySelector(“#table_2_4_filter > span > input”).value = userid;
}
</script>
<button onclick=”filluser()”>Rellenar usuario</button>

We plan to replace the button trrigger by “onload” but despite replacing the field content it doesnt “submit” it.

Any help on how can we submit a filter fiield using javascript?

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