setTimeout(function() {
let link = document.querySelectorAll('label'); //собираем все элементы label в nodelist
link = Array.from( link ).filter( e => (/Текст/i).test( e.textContent ) ); //переводим в массив и фильтруем по тексту
link[0].click(); //кликаем по первому элементу массива
});
<td class="x-table-layout-cell" role="presentation" align="LEFT" valign="TOP" style="position: static; padding-bottom: 5px;">
<div class="x-form-check-wrap x-form-field x-component " role="presentation" id="x-auto-1559" style="position: relative;">
<input type="radio" name="gxt.RadioGroup.4" value="" id="x-auto-1558" class=" x-form-radio" tabindex="0" style="position: relative; left: 0px; top: 1px;">
<label for="x-auto-1558" htmlfor="x-auto-1558" class="x-form-cb-label" style="position: relative; left: 0.78479px; top: -0.0104141px;">First Text</label>
</div>
</td>
<td class="x-table-layout-cell" role="presentation" align="LEFT" valign="TOP" style="position: static; padding-bottom: 5px;">
<div class="x-form-check-wrap x-form-field x-component " role="presentation" id="x-auto-1831" style="position: relative;">
<input type="radio" name="gxt.RadioGroup.8" value="" id="x-auto-1830" class=" x-form-radio" tabindex="0" style="position: relative; left: 0px; top: 1px;">
<label for="x-auto-1830" htmlfor="x-auto-1830" class="x-form-cb-label" style="position: relative; left: 0.78479px; top: -0.0104141px;">First Text </label>
</div>
</td>
<td class="x-table-layout-cell" role="presentation" align="LEFT" valign="TOP" style="position: static; padding-bottom: 5px;">
<div class="x-form-check-wrap x-form-field x-component " role="presentation" id="x-auto-1833" style="position: relative;">
<input type="radio" name="gxt.RadioGroup.8" value="" id="x-auto-1832" class=" x-form-radio" tabindex="0" style="position: relative; left: 0px; top: 1px;">
<label for="x-auto-1832" htmlfor="x-auto-1832" class="x-form-cb-label" style="position: relative; left: 0.78479px; top: -0.0104141px;">Second Text</label>
</div>
</td>