JSFiddle - React, Tailwind, and code Playground
HTML
<table>
<tr>
<td class="ms-formbody" vAlign="top">
FieldName="BP number"
FieldInternalName="BP_x0020_number"
FieldType="SPFieldText"
</td>
<td class="ms-formbody" vAlign="top">
ABCD FieldType="SPFieldText"
</td>
</tr>
</table>
JavaScript
alert($( 'td:contains("FieldInternalName=\"BP_x0020_number\"")').attr("class"));